I've never seen an anime con, or any con, disallow "professionals" from competing. o_O Where has this happened, Jia?
Professional qualifications put you in Master class. Which is a good place to keep them, so that those of us working our way up the ladder the hard way still have Journeyman in which to whet our skills. I understand, though, that smaller anime cons, and anime cons just starting out, may want to only have two divisions - Novice and Expert, perhaps. I have done that and plan to do it again at very small cons around here.
On the greater scale, of comparing the two genre cons...I think there is considerable merit to the point that anime cons have been putting the skit before the costume, and emphasizing skits. It's one of my major complaints about anime cons. But I don't think it's happening everywhere, and I do think that as time goes on, some of them are starting to get the clue that they can't run on skits alone. All cons handle that problem their own way - some split the skits off into a separate contest, some just alter the rule structure or put entry limits to try and encourage walk-ons or simply handle the influx of people.
I think a lot of it does have to do with the age of sci-fi cons. A good number of them have been around longer than ten years, whereas there are only a handful of anime cons who can claim that kind of longevity. The longer the con has been around the circuit, feeding off other cons in the same genre, the more likely it is that they've honed their masquerade rules and methods, and have kept directors with good track records for a long time. For some bizarre reason, new anime cons have this need to reinvent the wheel when there are tried and true methods already out there. There is no one way to run a masquerade, or a con, but there are all kinds of proven ways that anime cons can just copy or tap into. They ought to get advice or take pointers from the sci-fi cons with the good masquerades, but they don't. I blame it partly on ego, partly on ignorance. I'm sure a good number of people being asked to run masquerades at new anime cons don't know anything about masquerades, other than "every con has them." It's a tradition, and rightly so. But rather than sit at the knee of an established director and get some tips, they go and try to run it the way they think it ought to be run. Thus, the de-emphasis on costume craftsmanship and the complete lack of understanding of the mere existence of the ICG.
I don't think all sci-fi cons have their thing together, though. DragonCon notoriously does not. Smaller sci-fi cons that grew out of gaming or literature tend not to have as strictly-run masquerades, if they have them at all. Media and fandom cons, though, they know what's what, precisely because that's where a good number of hall costumes come from. Media recreations are the rage, have been since I started in 1999 and continue to be. Anime and video game cosplay is just an offshoot of that. Considering how much hall cosplay there is at anime cons, they ought to be the ones really streamlining the art of the masquerade, to showcase the best of the best. You can see a million half-assed Narutos in the hallway, but the stage is where they ought to be promoting the nine-tailed fox Naruto in the full fursuit.
There are a couple of things that can be done to increase the desire for more competent craftsmanship (and performance) judging at anime cons. A number of them are already starting down the road, but some need help. First of all, this forum is a good start. Word of mouth. The knowledgeable cosplayers who've been around the block should just start mentoring and giving advice constructively. Second, try to get veterans to judge at anime cons, because they can offer directors tips if the director is not already on the ball. Third, run more cosplay panels at cons to get people interested in serious costuming! Changing directors, changing judges, and changing rules is just one part of the picture. The competitors themselves - the congoing public - have to want to make better costumes, and have to have a reason to be encouraged to do so. The attitude of the cosplayer has to change as much as the people running and judging the masquerade.
That's more than enough for now.