It's not like the power users who currently use Firefox and yet dislike this stuff are going to switch away from Firefox, since there's nothing to switch to other than Chrome, which is clearly worse.
Personal anecdote, I didn't like Pocket being added to Firefox, but eventually I did start using it - only because it came from Mozilla. And I currently pay Mozilla money for Relay (along with VPN), which are examples of them expanding outside of their core browser features.