The end of 2015 is the only consistency he's shown. I understand your point, but for now Watkins potential is sky-high while his production has been less-than-impressive.
Fair enough.
Prima donna examples:
Complains to the media for more targets while also throwing his QB under the bus:
https://www.cbssports.com/nfl/news/sammy-watkins-to-bills-youre-making-me-look-bad-target-me-more/
Attacks fans for criticizing him, which I understand his frustration but to call fans 'losers' and tell them to go back to their 'little jobs' is such an arrogant thing to say:
http://www.wkbw.com/sports/bills/bills-watkins-goes-on-attack-on-critical-fans
Here's an article with him admitting he was selfish, and that his attitude hurt his relationship with the coaches and more importantly the team:
http://billswire.usatoday.com/2017/10/06/bills-sammy-watkins-selfish-rams/
Hopefully, his attitude has changed with the Rams. It sounds like he at least understood he was being selfish and arrogant in Buffalo. That's a good sign, and obviously people grow, so I'm not going to say he'll always be a prima donna, but his damage in Buffalo was done. The team's relationship with him was hurt, and McDermott and co. rightfully traded him away to get the negative energy away from the locker room.