I guess I am saying, is it fair to measure him this way? He has more than unusual and difficult challenges. He absolutely could improve and do better, and have made better choices. But he isn't perfect or infallible and he doesn't know the future. If you want to judge him so, perhaps reread the passage in Skin Games where Harry first talks to Michael after the first encounter with Tessa and reexamine the question in your thoughts. Michael says it best.
I don't know. The point is, there's normally a year between books. Now, I think we can cut Harry at least some slack for the last years, given that Jim has very carefully locked him away from the outside world after Changes and only with Skin Game he has had a chance for a few months to be in human civilization again. And I presume that much of that time, until Peace Talks, will have been spent hunting down Fomori and shutting down their operations in Chicago and the surrounding area (I wonder how many buildings have gone up in flame during that time), so we probaby should cut him some slack there, too. With so much to catch up on and not knowing what has happened between Ivy and Kincaid, it's easy to see why he wouldn't call, although he really owes Ivy one for what she did for him in Changes to save Maggie.
But over the course of the years before, Harry has shown signs of not keeping in contact with people who care about him. I think Peace Talks will be another point of change for him (obviously) and I hope he gets better about it.