In my eyes, he was 2-1. He was manhandling Alan Belcher the entire fight then he got a lucky submission. I realize a loss is a loss but he only convincingly loss against Bisping who is apparently a good fighter in the UFC, although I disagree.
I would agree with you, except for the fact that Kang has done this quite a bit before. Part of winning means not losing your concentration at crucial moments, even against lesser fighters. For example GSP proved the first Serra fight was a fluke with every fight after, but Kang has had a number of fights he was winning handily early, then lost, not just one.
He was beating Mousasi until he got submitted, same with Belcher, and there were a couple others, before Bisping. The guy has the talent to be a top level fighter, but he just doesn't seem to have the mental toughness. You can't fight part of a fight or part of a round, you have to be your best all the time if you want to play in the big leagues.
That said I think he should have gotten one more fight, but like I said, he has shown a pattern that seems to indicate a lack of some kind of focus, so I don't have too much sympathy.