You're making a lot of offensive assumptions here.
Casual players - of which I am undoubtedly one - are not indifferent. We care how our jobs play. I play most of the jobs, but I consider myself a healer main, and my healers have been fine and fun to play when I run content. I would no more dream of watching Netflix while playing than I would if I had guests around for dinner. I don't doubt there are players who do so, but I have encountered exactly one during the 11 years I've played this game.
It's fine to be unhappy with what you don't like about healers. It's not fine to make outrageous generalisations about the players who aren't unhappy. The truth is, most of them never come near the forums. They are out there playing the game they enjoy