Facebook maybe doesn't deactivate accounts for the fun of it (maybe). But they certainly do it willy-nilly if some algorithm or another gets any vague suspicion. Two examples I know of:
When Prince William got married, Facebook axed a bunch of profiles of women whose names happened to be Kate Middleton. Obviously, they're all fake.
I recently read of a guy struggling without success to get his account back. His crime? His name happens to be Mark Zuckerberg. No, not THAT Mark Zuckerberg. Obviously, HE'S a fake.
They might not ax people for fun, but they do it ham-handedly, and they don't care. They don't respond. They give you forms to fill, to feel like you're doing something. And nothing happens.
I had my account ONLY to engage in professional discussion in a professional group. That's all I did with it. I was in that group; I had no heated arguments; I deliberately had non Friends, and I posted no photographs. And somewhere, I violated some unspecified Term of Service.
Sorry, but your comment that if they axed you, you violated something smacks of blaming the victim. THEY kicked you out; YOU examine YOUR conscience, and glean and admit YOUR sins.