Why is most everything remastered?

I think it's a mistake to assume the original masters were intended by the artists.  In the great majority of cases, artists had little to no control over such things.  Record companies did.

What I meant by artist was composer or engineer.

@trentmemphis , that's true. The music business is very different today where you have mega stars having final say over their music..."use more Auto-Tune and add more compression."

In the past, the engineer and producer would record and mix the tracks and create a master. Before a record was cut, a mastering engineer would do his thing, then a test pressing was sent to a record label exec who would give final approval.

@voodoolounge 

Fair enough.  I'm not sure why the intentions of the person who happened to engineer the first master should be given priority over other, qualified mastering engineers' ideas, though.  In general, the choice of the original mastering engineer was based largely on who happened to be available when your record was ready for mastering, and within the budget. 

I don't think it was an artistic choice, or driven by who would make this or that particular record sound the best.  I imagine there were specialists within genres of music -- this guy knows how to master orchestral recordings, that guy knows how to master pop band recordings -- but I doubt there was much to the choice beyond that. 

And, as far as I know, the original masterings aren't being lost or thrown away.  They're still around.  If enough people like the original better than the remastering of a given record, somebody will put it into print sooner or later.

Let’s not forget that for vinyl anyway, the tapes used for the cutting were very often a copy with bass rolled of so the phono carts of the time could track it. New vinyl masters don’t require that since cartridges are better today and it’s a seen as luxury item with more spent on gear.
A to D converters back in the early days of digital were not nearly as good as now, and of course there’s higher transfers than 44.1/16.

I’m not saying some remasters don’t take a step backwards sonically, but there’s often no reason why it has to be that way.
A while back I heard the new Peter Gabriel remasters.
I would have bet that they were remixed from multi-track, since it was such a huge sonic upgrade from the first digital masterings. I posted on the Steve Hoffman forum about it and was told there was no remix, just a remaster.

Plus today we have better cables and power conditioning available, so if a remastering studio uses these, it should be beneficial.