Though, and not jumping on you personally, but it's a dangerous philosophy if you follow it too far.
I think a studio recording and a live performance are obviously going to be two different things, and when I'm recording I definitely do a lot of layering knowing that I'll never play half those parts live (I mean, I play instrumental rock, so odds are I won't play any of them live, since no one really goes out to see that stuff unless your name is Joe Satriani

). I don't have a problem with taking advantage of the ability to multitrack plus nearly unlimited tracks to add some extra depth and ambience to a studio recording, and then be prepared to strip a lot of that away to its more fundamental parts when it comes time to play live.
However, if you're using the recording studio to piece together a part that you know for a fact you can't pull off live... THAT I think is problematic. On some level, if you're writing songs then you have to be able to write stuff you can play, and be able to play the stuff you write. If you're doing heavy pitch-corection to a vocal performance that's just out of your register, or doing some serious tightening up of a drum performance that's just too complex or too fast for your abilities, or punching in sections of a riff because you can't jump from one position to the next fast enough but if you record each section seperately you can do it, then that's a problem, because someday, god forbid, maybe people will start to dig what yu're doing and you'll have to perform the material live, and you won't be able to. That's a problem.
I mean, yes, the studio and the stage are two different worlds... but they're certainly connected, and the former needs to keep the existence of the later in mind.
Full disclosure, I was working on a demo last night, and the bass part kicked my ass - I ended up having to do four or five punch-ins to get it right, partly because I had plans that night and was working in a hurry and didn't want to re-record an entire 6 1/2 minute performance, and partly because while it was within my technical ability to play, it was a bit outside my endurance (I'm not really a bassist) and my hand was cramping up like crazy by the time I finished. So, I'm a little bit of a hypocrite here, but for what it's worth I'm demoing for an album right now, and when I do go back to re-record for real with live drums, I'll have gotten some more practice in on the part (which I wrote that night, so some of the riffs were totally new to me) and should be able to hit it cleanly. But, at the same time, while I didn't nail it perfectly on the first take last night, had I spent any time practicing bass beforehand I should have been able to - if pushed, it's something I could play live. For me, that's the litmus test.
EDIT - and to reiterate Greg's point, if you're on a shoestring budget, then for all practical purposes studio and live are NOT two different worlds. You need to be able to go in there and nail it in one or two takes at most.