The Pats are one major ego driven organization that believes they can "fix" anybody. That might even be true most times, but some idiots are just too comfortable in their stupidity.
No doubt, and in those cases, the Pats cut ties with the player and move on. Not that the Pats "fix" everyone, but there IS some leadership in the locker room and coaching that seems to get people to shut up (mostly) and buy in. A good amount of that is probably also that they are playing for a shot at the Superbowl most of the time, so there's big incentive to shut up, stick to the program, and get the ring before moving on to a big contract elsewhere. That's what fixes most players (short term); they get to be seen behaving again, playing in big games, and winning. Some loser franchise then over-spends on them and the Pats move on to someone else.
I don't think it's entirely ego by the Pats, a bunch is just knowing that they've got something tangible that the players want (a shot at a ring, prime time games and attention, etc.), as well as knowing that if the Pats bring them in and they get cut for being a dick, or too stupid to figure out the playbook, then many of the other teams seem to accept that as the player being done and they don't usually get another chance. Sometimes the talent is big enough that they get another shot at it elsewhere, but if they were a problem elsewhere, and then the Pats can't make it worth either, not many teams sign up to be next on that trainwreck of a player...
Sometimes it works great (Moss, Dillion, etc.) and other times the Pats cut their losses and the player doesn't really recover (Adalius Thomas, Albert Haynesworth, Chad Ochocinco Johnson, etc.) Most of the time the Pats aren't counting on that rehab project to carry the team, so relatively easy to cut bait as well. Which is another thing hanging over the player and forcing good behavior; Belichick can and will cut just about anyone, pretty ruthless like that, so there's legitimate consequences. Some players are STILL too stupid to make it work, but they at least get a fair shot usually.
Edit: just to not dump a 3rd post in a row, because multi-quote doesn't seem to work for me at the moment...
Regarding comments about the Pats should suspend Brown themselves, etc. Thus far, it's an accusation and a Civil lawsuit, no criminal charges have been brought. I'd think that should factor in, at least until there's been some investigating on this. Different response if this had been a criminal complaint instead of a financial one, IMO. And it's not a statute of limitations thing, so still seems off to me that she went straight to trying for money instead of a criminal complaint if she'd been repeatedly sexually assaulted and then later raped. Personally, I'd be trying to get him thrown in jail and THEN soak him for all he's worth, but the jail part would be primary. But I'm sure there will be a lot more coming out on this, so we'll see. Everything so far has looked bad, and also made AB look like a complete moron/asshole even aside from the sexual bit, but it's early in the process.