Some responsibility is always on the players to execute the system, and some is always on the coaching staff to have a system that works. Some is on the GM to make sure the organization is aligned with the same vision from top to bottom, and that the coach has sufficient talent to work with.
In light of that, I don't really see how things have been "similar". The talent level of the team changed drastically from Hanlon to Boudreau, the philosophy changed drastically from Boudreau to Hunter, and Oates is a bad coach.
Just some responsibility is on the players?
This so typical of many in this fan base. Ovechkin can do no wrong, it has to be the coaching, wait it has to be all four coaches.
At some point I expect us to learn that the reason Dale Hunter didn't want to continue with this team, is because of the prima donna attitude of some of the players and that management and ownership was going to side with those players aka the young guns no matter what (because they were the face of the organization and put fannies in the seats).
Hunter realized that it was not the same NHL that it was when he had played the game, at least when it came to the Washington Capitals.
If Alex Ovechkin had been drafted by the Boston Bruins they would have traded him by now. The Bruins traded Phil Kessel because of questions about his work ethic (heck Randy Carlyle even made some comments about it in 24/7), Tyler Seguin was traded because the Bruins didn't believe he worked hard enough. The Capitals organization on the other hand will overlook such things with their star players and keep riding that same pony no matter what the results are and the fans will believe it has to all do with the coaching not the player.
BTW, I don't know if Oates will ever be a good NHL coach but this is definitely not the right fit or time for him in Washington.