+2
I can't speak for anyone but myself but a lot of the original trailer clips had me expecting very specific things. Juggernaut was support the way Boba Fett was support, yet was still perceived as a silent badass. Stepping out with rubber arms and a large foam helmet declaring, "I'm the Juggernaut, bitch." was a weak attempt at fan service conceit. My eyes still involuntarily roll just thinking about it. The casting didn't help at the time either.
Secondly, I never cared for the casting of storm. The character felt goofy, always off by a beat, and burdened with more importance than either she was actually written for or than Halle Berry could deliver. The 90's cartoon had more grounded leadership in voice acting alone. Could just be Berry exhaustion, but I honestly thought her character was weak compared the new spotlights given her.
Finally, Pheonix was a let down. I, and many friends, were expecting to see the Phoenix released and characterized with the trailers' staging of it as a potential climax, especially with how we were teased at the end of X2. yet all of what came after was still Jean being Jean only bad Jean.
Finally finally, fight sequences were mostly weightless with very silly-looking leaps and flights.
All my subjective judgments of course, but you need to view the reactions through the audience's perspective during release and whatever other cinematic contexts and attitudes might have existed at that time. Watching it today I may have no problem with it. I doubt it, but possible.
Maybe it's like eating pizza three days in a row then on day four, you're presented with ....another pizza. Only this time it's more mediocre than the first three so you swear off pizza never again. Pizza is alright. Even really mediocre pizza is acceptable now and I'll eat it without complaint. But in that specific moment, I simply wanted to throw up just thinking about another crappy pizza.