That is reassuring. I will try a different venue or two, perhaps that particular store is just populated with an exceptionally high percentage of former MtG players.
As for the behavior, really just a general lack of common courtesy. Little to no speaking, not greeting an opponent, being petulant and churlish when you don't draw what you think you should. The most recent example was someone sighing in exasperation and stating that "That has been settled in the FAQ for like 100 years now. Learn to play." I am relatively new to this particular game, and have yet to memorize each specific ruling. I am also somewhat impatient with rude people, so I called him out on it and explained that while appreciate the information I didn't appreciate him.
Honestly, I had enough escapees from their mother's basement in MtG. As frybender said, in MtG people were far, far too concerned with winning and not enough concerned with playing. I actually quit playing the pro-tour because despite the fact that I was making more money playing cards, it was far LESS pleasant than my full time job as a police officer, and that is saying something. On my last weekend playing MtG I placed 3rd, took home a $5k purse, and sold all of my cards the next day because it had been the most miserable 2 days of my life.
Here's to hoping that crowd stays in the store I found them in.