I think this is a lost cause. While the mainstream services may be blocked or forced to comply, there will always be hundreds of lesser-known tools and services offering the same features.

Ah, the good old "it's not perfect, therefore everything is meaningless" argument.

Because there will be someone trying to do bad things, we shouldn't bothering stopping anyone from doing bad things?

Don't kill the messenger. I didn't say we shouldn't try. I'm saying that this will be a whack-a-mole problem and banning one mainstream service won't solve it.