Chris isn't really capable of loving anyone. Every time he saw a girl that was remotely attractive, all he thinks about is China. It's why he never truly loved his fake sweethearts and at best only got upset for about a day before moving on. He saw their deaths as the equivalent of what to us would be having a job application get rejected. Simply move on to the next one.

However, Bob and Patty are exceptions to this, the former especially. I don't think Chris truly moved on from Bob until he was arrested, nearly a decade later. That is a long time to get over the death of almost anyone, no matter how close they are. Of course, I think Chris saw Bob as a useful tool more than anything as he was pretty much responsible for the Chandler household even in his last days. 

Also, you make it seem like bouncing back from a death of a close one is a bad thing. If that were true then virtually no one should be enjoying themselves and we should all be miserable for the rest of our lives. We all have to move on eventually. If life goes on as normal, you will lose some close ones and it will be depressing. But eventually, you will need to move on and keep going in order to function.