I guess when you have 8000 different amp models with 942 different stomp effects and 476.7 different modulation effects (not to mention delays and reverbs) this kind of thing becomes a necessity.

I Am all dinosaur. I Am old and couldn't even get into my Wonder Woman outfit this year. I sold my Marshall a couple of years ago.  too. I miss the old days when nothing was sequenced and there was no such thing as "presets"

Glyn Barnes
Like synth presets? - You have got to be able to twiddle knobs even if its just a little bit.

I guess I hadn't thought of it that way, being a guitar player. 
 
However, the number of parameters you have to adjust on a regular amp are usually far from overwhelming - drive/distortion and EQ...
 
I personally never felt that I had to perfectly match the sound of a song I was trying to learn or playing along with. Ballparking it is okay. Anyway, I only had one or two amp, and few pedals. Not owning a Mesa Boogie never prevented me from playing a Metallica song. My Marshall provided me with a heavy type of sound. Not owning a univibe didn't prevent me from playing Machine Gun - I'd just tweak my flanger to modulate things a bit.
 
It's about playing, not matching the sound. 
 
 

Rain
It's about playing, not matching the sound. 

 
Crap!  I KNEW I'd been doing something wrong all those years!!! 
 

But the sound has a lot to with how we play different genres.

Rimshot
But the sound has a lot to with how we play different genres.

Indeed. But we're talking about a genre, which is a bit more generic than an exact match. You don't NEED a Vox and a Rickenbaker to play I Want to Hold Your Hand. Of course, there are some set ups which will probably be more appropriate, but in the end, you could play it using a 7 String Ibanez and a Pignose.