Fuck this dressed-up, "This is gonna hurt me a lot more than it hurts you" mantra of the manipulative abuser.

I don't recall saying that ever. It's not this hurts me more than it hurts you, it's this hurts you but it could hurt you a lot more unless action is taken.

This attitude works in all walks of life. If a child breaks a window because he didn't realize that playing ball toward the house would result in a broken window, he's punished. If a child breaks a window knowing full well that playing ball toward the house would absolutely result in a broken window, he's punished harder.

If an employee makes a bad call and costs a company money, he will probably get written up. If a manager makes a bad call after being briefed that it was a bad call, he will probably lose his job.

Knowledge is accountability. This is the case in the aforementioned examples, and so is it the case on a spiritual level. If God is all loving, and he knows accountability will hurt you a lot more than it will help you if you're making certain decisions, then he would make a means by which for you to escape full accountability. Hence, excommunication.

Excommunication is about protecting the church from the spread of doubt. Period.

If the church wanted to protect itself from the spread of doubt, it would monitor this subreddit and other websites which have ex-Mormons on it, and silence those who went against it. It has never done this, and does not silence those within the church. If you have doubts, look for answers. There's nothing within the church's MO that says you can't voice your doubts.

It is barbaric, humiliating, and cruel.

My understanding of "barbaric" is something like torture and dismemberment for not believing as I do, something like what the 7th century teaches. Humiliation is a social construct. Cruelty is something done solely out of malice. Excommunication doesn't fall within any of those paradigms...