The time I lost my faith in Firefox was when the CEO of Mozilla got a huge pay increase, whilst firing many technical people at the same time. How can a tech company improve their product without those technical people? Oh, never mention the ever-decreasing number of Firefox users. Weren't the C-level people responsible for that?
Anyway, that was the moment when I realized Mozilla was just another company, not a flagship open source advocator or something. They're not even pretending anymore. Look at the sneaky attempts to integrate ads on Firefox. Look at the user experience being degraded every year. They are not listening to me, so I decided to not listen to them.