Whenever a player leaves a team a mythos arises that he sucked in the first place. So here is the thing. Jamie Collins wasn't having a good year during his contract season with the Pats. It was clear he was at an impass with his coaches and he was ready to move on from the Pats. I've mentioned a couple of times over the last 2 years that I was worried Collins didn't like living in NE most of the year. But it went further than that, and included working within the scheme as well.
So THIS season he had only one monster game (Houston), and was seeing his snap count diminish as guys like McClellin, Roberts and Van Noy took snaps from him in various situations. So when BB thought he could get something more than the HOPE they could get a compt 3 pick NEXT year, and wind up getting the an actual comp pick THIS year, he took it.
It'w my belief that BB heard, from his captains, that Collins' dissatisfaction with the coaches had grown audible in the locker room. Now sometimes this isn't much of an issue, but Collins was a quite well liked guy, and good friends with Hightower. So even though by that time, both sides knew that this was going to be his last season, BB worried that the lock room situation would fester. AND if you recall, it during those weeks just before Jamie was trade, that some of us were complaining that the defense didn't seem to have much enthusiasm even after good plays.
Since Collins has been gone the defensive excitement has reached almost a fevor pitch these last 2 weeks. They now seem like they are playing each game with literal joy. Even Hightower has commented on it. It can't be a coincidence.
All that being said, it would be a mistake to say Collins is a bad player. He had great seasons in 2014 and 2015. Sure we can point out individual plays, but the totality of those seasons were highly positive. This year....not so much and he was gone. And it was the right thing to do, though I'm sorry it didn't work out. I'm fairly certain that if hooks up with the right defensive system, he can have a great career. If he just chases the money, then it's anyone's guess.