Just spit balling some reasons people are saying that. I don't want to put to much thought into it.
1. QB with big contract coming off worst year of his career imo, now has another new coordinator and a new offense that he needs to learn. He also has some very justifiable off field distractions...
2. Maybe a stud RB? Maybe an injury prone RB? Who knows? Nothing to exciting behind him in case he does get hurt.
3. Bad offensive line last year, didn't add anything new to it this off season. Why would anyone expect it to get better?
4. Rumors of players not buying in to the new coaching regime.
5. Former NE assistants don't have a track record of success in the NFL. The coaching staff didn't impress me last season.
6. Defense was beyond inconsistent last year.
7. Holes that they had last year, still seem to be there.
8. Draft that most people consider to be one of the worst in the NFL. TE at #8 overall.
9. Marvin Jones coming off a down year. KG looks good when he's on but he vanishes at times. A injury prone former NE WR behind them and not much else.
10. Probably going to have to deal with curse of Hard Knocks.
11. 27 years since a playoff win...
I'm sure others can add to this list, but I think the doubters have pretty solid footing to base their opinions on.