I feel the same way. He only seems to hit one note.
If it's a note you like, though, no shame in enjoying it!
Come to think of it, it's kind of nice he's not your regular self-promoting Hollywood schmuck. I guess he's never tried to sell himself as something he's not.
I think he's genuine, and like Clint Eastwood, came to accept his range is more limited than his taste. Keanu is a deeper person than he is capable of playing on screen.