Is it live or is it?

Every concert I ever went to had a sound system consisting of horn loaded PA systems. So what are we doing spending all this cash in pursuit of feeling as if we are there when the entire chain of equipment is so different at home versus in any venue...?
As I only listen to unamplified acoustic music that has always been a total mystery to me !
I, too, listen to unamplified acoustic music but the mystery can be resolved. The horm-loaded systems are part of the music production/creation chain and their characteristics are included in the recording you buy. The home system should not have any characteristics, in the ideal, because they are part of a music reproduction/recreation chain.
Kr4 is right on that one. A lot of people make that mistake. The application is different,and you need to use the right tool for the right job.

The only thing I would add is that the OP's statement is usually not correct. Just because you're in the audience listening to the concert through a PA system, doesn't mean they're setting up mics and recording the PA system. Recording engineers usually tap into the signal at some point, such as the mixing board, before it goes to the PA. So what they're recording is not the same as what you here as a member of the audience.
Why would one pay large amounts of money to go 'hear' loud amplified music at concerts? Certainly not for the 'hearing'. It is all about begin there, nothing else. Do I go to live concerts? Yes, but only ones' that are in small settings where there is no amplification, these are mostly small jazz clubs. A perfect example of one such site in the Dizzy Club in Lincoln Center. You hear real live music.
If your home listening space were the size and shape of a concert hall venue, then you would probably use a horn based speaker array at home. If your home listening space is that of a typical domestic room, then there are more suitable choices. And yes, there is a difference between music production and music reproduction.
The main reason people go to rock concerts is its a social event. Thousands of people waving their arms is unison is more like a Nhurenburg Rally than a musical concert.
I thought the main reason people go to live rock concerts lately is to stand there and try to record them on their smart phones...The last few concerts I went to, I had a hard time seeing the performers on the stage, due to a sea of hundreds of people in front of me all holding their phones up in the air!
If you think rock concerts are bad, you should go to a classical concert. Its the closest you can get to dying without actually being dead. I guess the upside would be that its definitely not a social event. Its more like a mass funeral. I'd swear that half the people there were already wearing corpse paint.
zd542, your post reminds me, as if I'll ever forget, the experience of taking in Bach's Mass in B Minor with my wife and a friend and his wife that wanted to see a "classical concert". Bad choice! I had to contend with the kids and their giggling, it became too much and we had to leave before intermission. Our immediate neighbors were NOT amused, in their deathly silence.
I have worked in the professional audio industry for many years. I have designed and tuned many systems for 60,000-70,000 people as well as many smaller ones. While horns were once much more popular than they are today, even many of the line arrays that are almost always used now, have small horns in them. You don't really see the large horns that were once so popular any more. The reason we use horns is not because they improve the sound, it is for increased volume per watt and most importantly for pattern control. A horn allows you to define (more or less) the coverage pattern of where the sound is best heard. We used different horns for different reasons, primarily where we each speaker is covering. We like constant directivity as that means that you are getting the same coverage pattern across a broad frequency range. The real trick is at the crossover point where you are crossing between two different drivers.

I also have designed a lot of recording studios. There, you will rarely see horns being used. Honestly they don't generally sound as good as direct radiators.

In the studio, we are concerned with accuracy of what we are hearing. We want to hear exactly what is being recorded. For live sound, we want good, consistent coverage, and may use the system to enhance things, such as when we use massive subwoofers. At home, you really have the most freedom. You want it to sound pleasant to YOUR ears. If you like a certain characteristic, then go ahead and use equipment that emphasizes that. It is just for enjoyment. How lucky is that?
So really, you are best off sticking with well designed speakers that were developed for home listening.

As far as why people go to concerts today, it is for the same reasons people have always done so. I currently find myself at FOH at large concerts for many of the most popular acts in all genres including EDM, Hip Hop, Reggae, Jazz, Country, Rock, Metal, etc. And while it is always partly about the scene, the party, the effects, getting high, etc. it is still mostly about enjoying music. A lot of the shows I am at have very young audiences. And they are having the same good time my generation had back when. And they are very much there for the music. While I personally enjoy a small venue with live acoustic music, there is something to be said for the MUSICAL experience that can only be achieved with a very large sound system in a great venue.

Best post I've read in a long time. (Not counting any of Al's, of course.)
The last bunch of years I have been disgusted with most amplified live concerts, even most rock concerts. Too bad, as I love listening to live music. But so much of it is poorly amplified and/or mixed I just get pissed off and either suffer through it (making faces and sometimes loud comments), or just leave. I think for two reasons: 1. I have become a more educated, discernable (a.k.a. snobbish) listener since acquiring a decent home rig and thus am far less tolerant of poor sound; and 2. the folks running the sound boards are either deaf, ignorant, or just don't care.

What I really hate is when a performance is amplified when there is absolutely no need. For example is smaller venues with acoustic instruments. Even if well done, I still hate it, knowing unamplified is best (when possible).

These days I much prefer my rig over most any live concert and often just stay home to listen.
Live concerts are like most things...there's the good, the bad, and the ugly.
Mapman wrote: Live concerts are like most things...there's the good, the bad, and the ugly.
Yes, and that applies to all genres, including the ones that some of us don't like. ;-)
That is right MapMan, just like anything, there is a big range at concerts. Last year I heard a lot of shows that sounded great and had really skilled mixers, as well as lots of mediocre ones and some poor ones. Some of the young generation of FOH engineers are really talented. I have three nights with Bass Nectar using the EAW Anya system this weekend. I am checking that system out at sound check. It is known for doing an amazing job of steering low frequency, which is really hard to do.

I also like Coli's comments. That is the whole point of this hobby. He may love horns and they may not be my favorite choice. But in the home, if it sounds good to you then it is just right! Nobody is wrong! In the pro world, you have so many factors to consider other than your own personal taste. I am curious Coli, what norm speakers are you listening to? I will have to keep my ears open for them.