Well first, he has an immense grudge against Ricciardi that stems more from JP's attitude towards the Toronto media (as in, he's willing to talk to bigtime american media but thinks Toronto media are small town) rather than his actual managerial decisions. He's made some bad decisions lately, but he's also a GM grasping at straws and this grudge goes back prior to this season. I think it's horribly unprofessional for personal grudges to play out in the way Griffin writes.
Second, the guy refuses to acknowledge the growth in statistics that have helped people better understand the game. The guy is all about Wins and RBIs, stats that don't tell you anything really and he has openly admitted that he dislikes even the next tier of stats like WHIPs, nevermind stats like OPS+ that involve some formulas that he probably can't wrap his head around. Ya, stats aren't everything, but in a game like baseball where the game is static and repetitive they tell a lot of the story. To refuse to acknowledge that is a bit absurd I think.
Finally i just don't think he's a good baseball mind. For a Jays beat writer he knows very little about prospects including saying things like "Snider has recently struggled in Vegas" when the guy was actually on the DL with a back injury. Of course he was struggling, he wasn't playing! I think if you're a beat writer for any team you need to know the organization. If everyday fans know what is going on in Vegas or New Hampshire with those teams and those prospects, there's no excuse for a guy who is paid to do it to not know what's going on.
He's just never impressed me, and I find I get more from the hardcore fans in terms of real news than anything Griffin ever provides.