well, in my personal opinion they shot themselves in the foot when:

- they ditch their own extension system (which was far more powerful) to go hunt for leprechauns with google "unified extensions system" (read Google-Controled extensions system)

- when they stopped servo development (yeah... there is lack of money, but not to pay the big ones on the top, right)

- They give the boot to Brendan Eich (yeah... the Brave browser guy)

- They spend coding time with useless features (oh i can mention a few... but lets start with those colorful themes that no one cares about..........)

- i can go on and on... and on.......

but... all in all, i'm HEAVY a Firefox user!!! (because there is nothing else to choose from)