I'm a little lost trying to figure out how nobody playing Assault concludes that the MP is "trash in every way possible". Your topic title is correct - nobody plays assault mode. I've played it when I could and think the game mode is just fine - but I get why most people don't play it, they don't have the patience any longer for a game mode that ends the play for them if they get killed. So, although I like the game mode... and I think the game mode works properly and as intended... it is the players who are choosing not to play it.
The only fault I find on Crytek and EA for this one is overestimating modern gamers attention span and patience. They presumed that players might enjoy a mode that requires teamwork, clever tactics and extreme caution. Seems most go, "Crap, I'm dead... oh man, I'm not playing anymore. I'm gonna leave this and play TDM now."
So, I don't think the MP is trash at all. It's quite enjoyable. It has problems... but nothing compared to many other recent titles.