Bolded for emphasis, I think you're missing the point when people say things like "fuck Bungie". I'm not supporting statements like that, since I always think actual discourse and discussion on what you actually don't like and problems you have is a superior option, but you're totally glossing over the point many of these people are making.
They AREN'T saying "fuck Bungie, I hate Destiny 2", they're saying "fuck Bungie, I like Destiny 2 but they keep making bad decisions making it worse". These are often people who like/love the game, want to keep playing it, but are met at every turn with poor decisions on Bungie's part that seem to be going in the wrong direction, and it is frustrating. Things like not fixing the Nightfall bug, which eliminates an entire 25% of their prestige nightfall offerings, can understandably frustrate people. Similarly, things they spent 3 years perfecting in D1 being rolled back to an even worse state in D2 despite the team leads for TTK and D2 being the same are also frustrating.
It is very easy to like a game, and dislike the direction the developer is taking it, or dislike the lack of support to issues you have with it, in which case you are totally allowed to play the game while still being irritated with the developer. Again, as I said "fuck Bungie" is too vague and useless, but honestly there's not much wrong with "fuck Bungie for not fixing or even addressing this Nightfall bug in 4 weeks and leaving an entire aspect of the game unplayable". Now as soon as the "so and so should be fired" or worse, the death threats start flying is when I lose all faith in people posting about this stuff, that is always unacceptable...