I think troubled players can be rehabilitated in a way, I'd call it just playing them. Of course if they are skipping practice or whatever there should be some sort of punishment, but for the most part I do not expect a hockey team that has 23-25 guys and a prospect pool that has 23-25 kids to be some sort of angelic bunch where they all get along or do not have some attitude. I find that to just be the nature of professional sports.
Players like Kane, both of them, Avery, Downie, Carter, Richards, etc cause some issues, yet some teams are able to find ways to deal with that rather than turn the player into a non asset. At some point the Rangers are going to have to choose talent or wholesomeness(for as lack of better word), teams that have won cups (or teams in other pro sports who won their version of the championship) have had players that are troublesome on them, more than one or two players that would otherwise likely be perceived as jerks or whatever.
If the philosophy is, the team will be filled with character, leadership, whatever traits over talent where does that leave the Rangers chances of eventually winning a cup when other teams are able to deal with difficult talented players and the Rangers are not?
I don't know why you think that's the case. We don't even know why or to what extent there's a problem with DeAngelo. However, we obviously don't have some rock-solid commitment to character at all costs or else we wouldn't have taken the gamble on acquiring DeAngelo in the first place.
You're making it out to be an either/or choice, like the Rangers have to choose character or talent. They can choose both. How many incredibly talented guys play in the NHL without characters concerns? Probably 100x more than those who have documented character issues. I mean sure, you can find a handful of stars who have done bad things either before or after they made it, but you can find tons more who haven't. I don't think it's a problem that the Rangers are focused on the latter group.
Patty Kane is a tool. He was also an established star when he ran into issues. Detroit got rid of Avery pretty early on because they said he didn't respect the game; LA eventually moved on after the bullying and refusing to practice. Downie is a dirtbag, and should have been thrown out of the NHL years ago--I would not take him on my team under any circumstance. Carter got traded to a place he didn't want to be right before his NTC kicked in, sulked and loafed through his tenure in Columbus, so they had enough and got rid of him. Richards was a star when the sex and partying stuff picked up. Then after turning it around in LA, he gets terminated for drugs. Evander was an established player long before the assault stuff.
From those examples, Downie is the only guy who wasn't already being a productive player established in the league when his issues cropped up (and he's just awful). He's the only parallel to DeAngelo (far worse though). Kane(s), Carter, Richards, even Avery--they all had "made it." And even then, the latter three were given up on, some multiple times. DeAngelo hasn't made it as a productive regular. He doesn't get the same leeway.
Who was Washington's bad boy? Wilson? Dirty player, but there were never character or work ethic concerns with him. Ovechkin is lazy at times. He's also possibly the greatest goal scorer ever. Pittsburgh before that? Sestito is a thug, but same thing, not a "difficult" player. And then your guys--Chicago with Kane, LA with Richards. Established stars who got into shit. I have no doubt that Rangers would be playing the Patty Kane or Mike Richards of 2009, despite their issues. Either way, it's not like you need "troubled players" to win. You can win with a good character group.
We've also drafted Lakatos, who has issues, and they've ruined his chances of every getting a deal. We took Sean Day, a guy known, right or wrong, for being fat and lazy and not committed to practicing. They only got rid of Robin Kovacs because he asked to be released. A couple years prior they took Duclair. They have no problem taking chances on guys, or working with guys with problems. Just because some people feel it's wrong to sit out DeAngelo for whatever issues he's having without even knowing what those issues are, doesn't make it so.