See I think it comes down to what the community wants to be the accepted norms and standards. I will happily play against and with unfinished/unpainted armies in club and friendly games as will 99% of the NZ community (including those who can paint masterpiece armies.) I guess down here we have a different view when it comes to tournaments as we see these as our exposure and publicising to the public and potential recruits. Having painted armies on the table shows the dedication and artistry in the hobby and just plain looks better to observers.
That aside no one would bat an eye at letting a newbie use an unpainted/unfinished army. The problem myself and the rest of the cast have is individuals who either don't paint their army or do so to a terrible standard and then use it for years. Sure they may get done by paint scores, but its just lazy and doesn't do the hobby scene any real good. I totally agree that tournaments are mostly about gaming which is why I'm for capped painting scores and against an uncapped system. That doesn't take away from the fact that at public events I believe that there's a standard which should generally be met.
It's interesting when I'm at events where there are other games being played the different attitudes towards painting. Warmahordes tends to have plenty of players playing with bare-metal figures, Warhammer 40k and Fantasy for the most part have a range of armies on show, from shockers to masterpieces. Interestingly enough it is the historicals (with FoW being the best example) that tends to have the most visually appealing games and I don't think I've ever seen a game of FoW where I didn't think all the armies and terrain involved didn't look fantastic. I can't say the same for Fantasy. In fact I'm nearly positive that most FoW tournaments require painted armies, are they a bunch of spoiled whiners?
I hope we don't come off as too spoiled, and I can assure you our motivations have nothing to do with not wanting to lose to an unpainted army. All of us actively umpire/run events, help out at clubs and scout for new players. I've run (and will again) events where unpainted armies were allowed specifically to get more people into the hobby as I wholeheartedly agree that bringing new blood in is crucial. Our main problem is when an unpainted/unfinished army gets used year after year or when it's clearly been rushed together to jump on a bandwagon. Call us what you want, but we do think the game is meant to be played with painted miniatures.
Curiously enough, in NZ at least, when the Evil Empire was still running tournaments you had to bring painted armies. So yeah, I think it's the decision of whoever is putting the time and effort into organising the tourney to make. People are always welcome to vote with their feet, run their own tournaments or paint their army.