It's interesting, but you generally do not see many of the unclean clueless gamers in Portland. I have never in reality encountered many of the stereotypes you judge. The last two FNM that I went to the players were made up of mostly your average jeans and t-shirt guys (fairly fit and well groomed), the occasional awkward skinny nerd type, a couple of beardy hipster types (well groomed), and two trans players. There was also a smattering of women, but they were playing draft so I did not really pay attention to their appearance. From what I hear from Galspanic and others that is pretty typical around here, though some shops are a bit more cave-like in ambiance. The shop I go to is huge, open, clean, and attracts all kinds of gamers- there is even a room where they have craft beers on tap.
The majority of the regulars are average t-shirt and jeans person- both fit and not so fit (this would be me, gained a lot of weight drinking and never got it off). This is most certainly me, and this group really makes me proud to be a gamer. They are still usually guys, but there are women too, and the guys are usually well rounded enough to not treat women as if there are a new species. They generally just want to blow off some steam and have a fun game, and are not too judgmental about who they play with. I find them open, friendly, and really easy to get a game going with even if you have never met. I am quite comfortable socially, so I have no problem approaching anyone really, but these folks are the kind that will come up and say hi next time they see you in a shop. They generally don't trade a ton, and are don't spend a lot of time online researching decks (obviously I am an anomaly here). Needless to say grooming and cleanliness are at or above social norms here.
I think the premise that the only reason a person says it doesn't stink in their shop is because they stink is lazy stereotyping. My training is as a registered nurse- in which cleanliness is one of the most important habits, and my wife (also a nurse) would not let me near her if I smelled, and I shower at least once a day, but I must be the stink-master general because I don't think the people at my FNM smell? That is absurd.
I want to be clear- I am not defending smelly anything, I am stating that the stereotype that MTG players are less clean and well groomed than average people of the same age has not been substantiated in my experience.
For reference, here is the shop I generally go to. As you can see it is large, airy, bright, and clean. The other shop I sometimes go to is about half the size, but still clean and well maintained (as you can see from these photos). I know for a fact that you can find shops like these in Seattle and Northern California, and I am sure they are getting more common across the country.
I think threads like this always stem from a some self-loathing of some players who still hold a bit of shame about playing the game, and if comes out as wanting to make sure that other people don't think they are a freak. As such they point out others as detrimental because they fear others thinking they are part of this population.