I don't think he's blaming anyone either. The fact he's acknowledging there are probably people working at FB who shouldn't be suggests you're wrong and that for years FB has kept people despite it not being the company's best interests.
Tbh I wish all companies were honest about why they're cutting back. I know I've been given BS reasons for being cut before and I've also been given no notice or warning. This seems relatively honest and direct in comparison. Those providing value will be fine, those who are not will be let go - isn't this how employment should function?