The short version...
This guy (Atwood) is a long time collector and has a ridiculous collection of sealed in box games, including several shipping boxes (6 games in each) that are still sealed. He enjoys the hobby and doesn't really brag about his collection.
Lately, some of the top dogs of collecting have been doing shady dealings (such as buying several copies of rare games) in order to drive up the value of games like Stadium Events, Bonk, Dinosaur Peak, etc. Atwood has called these guys out before and basically feels games shouldn't be an investment. At least not when you're buying 20 copies of an already rare game so you can bump up the resell price.
Having had enough, Atwood stated that he will sell some of his mighty collection - flooding the market with these super rare and expensive games. Now "flooded" is a generous term, but when only, say, 15 sealed copies of Stadium Events are known to exist, and this guy introduces 12 more into the market, the value on this game (as well as the open box version) is going to drop considerably. It will still cost a fortune, but significantly less than what they are going for now, meaning flippers may not make back the thousands they invested.
As for why he has been banned, my guess is it was because he pissed off the elitists who run the NA forums. I think one of them is someone Atwood has called out in the past for this type of stuff.
Anyway, I don't know if the guy is a hero or an asshole, but he sounds awesome, and I would love to check out this guy's house just to see this stuff with my own eyes.