I don't know that it was the roundtable that got it rolling, this ball has been in motion for a long time, and it will continue to roll.
It's gonna happen when you have people who come to these forums that aren't the most knowledgeable about the sport. Because of this, I believe there are a good number of people who have some sort of brand loyalty towards one of the games. I imagine that those who love the sport itself see what each game brings to the table, and where each game is different. Everyone is generally in the same "camp", as it were. There might be disagreement, but there is no belligerence.
I personally know people who think FIFA is a fun game because it's FIFA, not because it's soccer. And while that's totally fine, it breeds a sense of conflict between the two games.
It's sad, but it is what it is. Some people might be able to handle it, but everyone will not be able to have a civil discussion on two opposing products, be it politics, religion, or videogames. This thread has taught me that. Also, I won't call it out, but there is some serious hypocrisy in this thread; that's the kind of stuff I'm talking about. Blind hate towards one game or the other.