I can't help but think the designers do not care. I'm guessing the UI/UX folks at Mozilla think only a loud minority of users are protesting the incessant redes

I can't help but think the designers do not care. I'm guessing the UI/UX folks at Mozilla think only a loud minority of users are protesting the incessant redesigns. They probably look towards what Apple and Google do and believe they have to follow trends or be left behind. They also probably want to be seen as bold and innovative - so damn the metaphorical torpedoes, full speed ahead! Edit: The kind of feedback they're willing to accept is probably only barely impactful. Suggest going back to the old tab bar? Sorry, but you'll learn to love it and we aren't changing it. Suggest a slightly different shade of gray for the edge of the rounded tab bar? They might just take the suggestion. That kind of thing.