The "sim" vs "casual" thing is a bit overblown imo. I've been thinking about that conversation recently in a different way. I'll give you an example that I think can clear up what I'm saying. Take WWE 2k wrestling, we would't consider that a "sim" simulation sports game, would you agree? However, the characters move with "real world" physics because the game is based on "real world" characters/people. For the most part, aside from occasional clipping or sliding that happens in games, the characters move "realistically" like humans are supposed to move in general.
I would say a huge portion of the fan base for that game could be considered "casual" no? It has no major issues holding peoples attention (not that I can see at least), even though the characters move with "weight" and take actual steps around the ring. Hope I'm making sense here. MMA, boxing, basketball, etc aren't fantasy based games like your Mortal Kombats, Street Fighters, etc. The base foundation for games that are emulating "real world" sports should always be "real world" physics integration, UNLESS in a few cases, its an arcade based title like NBA Street, NFL Blitz, etc that CLEARLY is making a cartoon representation of the sport, those can be given a pass when it comes to movement.
My issue is (and this is what has stopped me from purchasing up to this point), is the complete disregard for proper character movement for a game of this nature. It's unacceptable, and I don't think it has much to do with being "casual" or "sim" oriented, its the fact that it isn't a fantasy based game. I'm certainly not the only one with this sentiment, and to be honest, I don't think "casuals" would notice much, and they'll purchase regardless. You'll actually increase your sales by focusing on the purists of the sports (which are HUGE silent demographics).
I'll close with this. Let's say you have 500,000 casuals, these guys/gals don't have much attention to detail (no slight, just speaking facts). You're going to get those 500,000 sales for EVERY release regardless just because, no matter how the physics work. Now let's say you have 250,000 more purists who DONT purchase because the game physics are terrible.
I would much rather get the foundation of the game correct (physics) for the purists which would get me all 750,000 sales, instead of leaving the purists out of the equation and taking the 500,000 sales. So yes, the purists may be less people (who knows), but they could possibly double your sales. These developers shoot themselves in the foot without even realizing it imo. Now all of the "casuals" are having a grand time lol, but the company just missed out on an entire demographic of people that they could have captured, while at the same time not having to worry about the casual players who were going to buy it anyway lol. Hope that makes sense.