I never meant decent in terms of ability, definitely not, there probably isn't anything on the guitar Tremonti couldn't do. He's a technical master. But in terms of songs? Nope, he's not got it. I can't think of an amazing Tremonti song. This kind of reminds me of the Blackmore vs Satriani debate, Satriani is far more technical, but in terms of songs, not even a contest.
The funny thing is, Mark cares more about songwriting than guitar playing. Check this, and tell me this isn't a great song.
I don't think anyone's mind is gonna change, but if you haven't really dug into Mark, you might be surprised.