Why has amplifier power become a big issue

If you choose speakers of high efficiency, 100db+ you can use amps with just a few watts of power. Roger Russel of Mcintosh speaker fame talked about how he was tasked with building speakers that could handle 100's of watts. The reason? To sell big power Amps that they also produced. Speakers can be had with very high efficiency and that's part of the reason the single ended amp is being made by quite a few companies these days.

Its a matter of choice, sure if you want a 500 watt class A Pass Amp/Space Heater its readily available... He also has tiny 5 watt amps under the First Watt brand. 

I guess that for my room in my NYC apartment listening to the music I listen to (small jazz quartet/quintet) the 50 watt amp does it for me. I have other amps up to 200 watts per channel from other manufacturers that I can use if the mood strikes. I just wanted to ask to see what has changed in peoples perception of sound that keeps the power output on some amps going up. Vandersteens aren't the most efficient speakers out but they don't present to many problems for most amps. I know listening to volumes greater than 85 db for long periods of time isn't great for your hearing. I listen at volumes that require a couple of watts and the transients require maybe 20 watts for short bursts and that can be covered by my 50 watt amp, no?

Nothings has really changed.  Loudspeakers with a sensitivity  in the mid-80s will sound perfectly fine with 30-50wpc.  Of course these same loudspeakers will sound better with 150-200wpc when played at louder volume levels.  However, if your typical listen level is 75-85dB, then 30-50wpc is sufficient for most types of music.

It's been my experience that if high volumes levels are required that high sensitivity loudspeakers is a better route than high wattage amps.

Modern Class D amps are very efficient and solve the problem nicely.    Without them I'd be more prone to go tube amp (not efficient generally) and high efficiency speakers to pick up the slack there. 

Power specification is very vague.  Average music power is only a few percent of the peak power.  Headroom of the amplifier is very important but most of the time not even specified.  

I also enjoy  my class D amp, especially at lower volume.  It does not loose composure, provides perfect imaging and strong bass.  It is closer to tube amp, in sound, than any SS amp I had.  In addition many amps, including my class D amp, have soft clipping, protecting tweeter from excessive amount of HF harmonics.