Yeah, it's blurred too much. It's also obviously not a natural lens blur, which is not impossible to achieve in software, but takes more work. Another BIG problem is that the edge around the guy is not done well. Parts of him are bleeding into the blur, but mostly there are still sharp areas around him from the background, and so it comes off as totally fake. Same thing in the hair - background is obviously faked.
To do this right, you've got to make a true composite. To do that, you duplicate the layer, then mask the guy to isolate him from the background (there's a TON to learn on this part alone, to do it well), then take the background and blur it and SHRINK it slightly behind him so that the blur from the guy gets hidden behind him - or just replace the background altogether.