All of these guys deserve to be in, no question about it. The credentials of Bruno, Backlund, and Savage are unquestioned for what a Hall of Famer should have. The Warrior isn't quite in that same league, but, like it or not, the Warrior is one of the most unforgettable characters in wrestling history.
The personal issues have a lot to do with it. Bruno hates Vince, unfortunately. He also made comments a few years ago about the HOF being a joke because Pete Rose is in it (kind of agree with him) and because it's just a plaque, there isn't an actual HOF building that one could visit. Now as far as that point is concerned, I can understand his point of view, but I don't think there will ever be one. I remember Shane McMahon saying it was something they'd like to do with the amount of stuff they've collected over the years, but in this economy I just don't see it happening.
Wikipedia claims that Backlund has been offered the HOF, but has turned it down. There was no source for this, but if JR said on the Legends show that it's because Backlund feels he has another run in him, well, I believe that since Backlund is a little crazy. He'll definitely be there one day.
As for Savage, there's never been any confirmation as to what the issue is between them. Personally, I have to think it's something serious, because Vince has given everyone second/third/fourth/etc. chances. Case in point is the Warrior. I've read where it was thought that the heat had to do with the way Savage left for WCW in 1994. I can't really think that's the issue, because that seems so trivial in the grand scheme of things. About those Stephanie rumors, well, they are just rumors. And at the same time, I can't help but think there may be some truth to them. Why else would Vince want nothing to do with a guy who was one of the top superstars for years? I'm actually still amazed they're doing a DVD release for him this year. I really hope that whatever difference is there gets resolved. Savage would be the best candidate as the headline guy for the HOF next year, unless they intend to induct Undertaker or Shawn Michaels while still active, or if they can somehow convince The Rock to come back to be inducted.
Warrior is just so controversial, naturally. I say he deserves to be in because he had a huge impact on the business. In all honesty, I think Vince would be willing to induct Warrior, if not for the backlash he might face from people like Triple H and Ric Flair. I also think that as of right now Warrior would reject V ince, since he's probably bitter of the Self Destruction of the Ultimate Warrior DVD released a few years ago.
Off this topic, someone mentioned how "average" people can get in, I think that's true to a certain extent, but not entirely. The people in the HOF that I consider to be questionable as HOF material are Johnny Rodz, James Dudley, Baron Mikel Scicluna, Pete Rose, William Perry, Bill Watts and Koko B. Ware.