First off, lol, I am kind of a musician. I've been writing song lyrics for a year now and am learning to play acoustic guitar as well. I might eventually take up another instrument, but for now, I'm focusing on acoustic and then I'll buy myself an electric and try to shred like Mark.
Secondly, I wouldn't say that Stapp likes less in depth music. You do know that he is a big fan of U2, right? He also was/is a big fan of the Doors. I haven't really listened to much Doors stuff, but I do know that U2 has some pretty in depth, creative music. It's possible that Stapp forced Tremonti to cut back on his soloing, as Stapp himself has said that he isn't a big fan of solos. But, Tremonti is his own man, so I kinda doubt he'd let Stapp tell him what to do when it comes to playing his guitar. However, he would have to listen to Wind-up, so that's why I think Wind-Up is to blame.