although I can see how this can be abused. Imagine if I create 10000+ spam Facebook accounts and they all get disabled, am I entitled to a written explanation for why each account got disabled?
This just teaches the abusive users which behavior was caught, so they can learn to be better at evading that scrutiny in the future. It is completely counterproductive for a company to provided banned users with a detailed reason for their ban.
You might even require a $5 bond to appeal or something, to prevent spurious appeals.