I see how it might seem like that, but that's not how it's intended at all.
The idea of saying boosts appreciated is if someone has an especially strong reason for something to be shared, they can add this to the post.
It's also intended for people who have written something personal which may or may not seem polite to boost, to reassure people that boosting is indeed ok.
Obviously if someone puts that on all of their posts that's sort of abusing it, but most people don't do that.