For me, it has to do with all the corporate, mass produced fandom we see today. I live in Orlando and go to Disney pretty regularly, and the number of people I see who have to throw on some random Marvel or Star Wars shirt before going to the park is insane.
I've never understood fandom like that, as I've never felt the need to walk around blasting my preferences in people's faces. But, I appreciate it in its natural form, e.g. someone walking around in a shirt they got in a promotion or at an event or something.
So back to Avatar: I see a soulless, very blah product. And I see that they are investing a ton of money to make this series a success. So when I see people on here championing some very bland franchise as if it's the most exciting thing in the world, I'm completely flabbergasted. I literally cannot empathize with that position.
If the movie comes out and is enjoyable and fun, great. But I'm not going to sit back and act as though the Avatar franchise is anything more than an investment for a film studio, or that it's some force of nature that will change art as we know it.
To me, it would be like people being super excited about a new phone when the last model was just a generic, average phone. It doesn't make sense in my brain.
It just feels like people want something, anything to be a fan of today.
I'd argue the opposite tbh, yeah people like to follow entertaining media. But I'd say the tribalism around media franchises more often results in people wanting something to hate on.
As for Avatar, I think the critical and commercial success suggests it's anything but bland.