I think that's the point some people are missing. I mean, what can you do when you live in an apartment, or when you have a wife and kids. Can't always turn it up. My current amp, I've never turned higher than 4.5 (it is a 150 watt amp, so even that is kinda loud). I've looked into isolation booths, too, and they run $1500 and up. Sorry, but that's a heck of a lot of money for home recording just to keep from bothering the family or neighbors. I have that rectifier thread going, and some have suggested an isolation booth (too expensive), some have suggested getting a little bitty amp (which is probably a really good idea, actually, but where's the fun in that). Some of the later posts say don't even bother getting a tube amp if you can't crank it. That's discouraging. So, frankly, I'm about ready to just grab a Vetta II. <gasp! - as the purists grab their pitchforks to chase me out of HR.com> But I can get one for 700-800 and I don't have to turn it up to 9. Would I prefer a tube amp? Of course! That's why I started that other thread. But there is a place for pods/vettas/etc., and now that they are upgradeable, they get better every year. If (when

) I get signed to that major record label contract, I'll record with the real thing.
But to get back to the point, look at the context in which people talk about pods/vettas. Most often it's because of ease of portability to go jam at a bud's house, or to do a backyard gig, or a small club or something - where the acoustics don't matter or suck anyway, and nobody can tell the difference. Or to do home recording.
I used to have a Korg effects processor. When I'd go over to my drummer's house, all I'd bring would be my guitar, a couple cables, and that processor. We'd run it into the pa system he had set up in the basement around his kit, and off we'd go. No lugging heads or cabs around. I could carry everything in 2 hands. Get set up in a couple minutes, break down in a couple minutes. Did it give me the most amazing sound you've ever heard? No. Did it allow me to easilly and quickly get over to my drummer's place and spend time jamming, and practicing, and creating? Heck yeah. Would I go into a professional studio with that setup? Heck no.
There's a reason these things are popular, especially among the home recording community. And that's because you can't always crank up the volume when doing demos out of the house. It's not the end of music.