He may have Napalmed the bridge with ESPN back in 1998, but that got rebuilt, and he went back, first to ESPN Radio, then to ESPN 2. His departure last year was by all accounts, completely civil. Olbermann didn't burn the bridge with FSN, Rupert Murdoch did, he admitted as much. He may have burned the bridge with MSNBC when he left in 1999, but the 2011 departure doesn't seem to have been that bad, if MSNBC has approached him about coming back for a third time. As for Current TV, well it doesn't exist anymore, they fell apart because of bad management, and even Al Jazeera couldn't make a decent American channel out of the remnants, so who was most at fault there?
Sure, he has had his problems, and his arguments, but from the information I've seen, it's mostly been from the position of trying to do the right thing. Sometimes there's been some selfishness, but we're all guilty of that from time to time, and anybody who says they aren't guilty of that at times is lying through their teeth. Too much trust is put in gossip columns and unproven and unprovable stories that we should be very careful about believing. Remember, it takes two people to make an argument.