I like the composition (I might have opened it up just a smidge, but not much), but I agree that for the unbiased observer there isn't enough to grab the attention here. This kind of a closeup would really work if
a) the entire face was super sharp (this one is decently sharp, but not super sharp)
b) the face itself had something more interesting going on (like deep laugh lines, or even if he just doesn't shave for a day and you can get sharp stubble)
and/or c) the sunglasses weren't present, so we could see the eyes and any detail/emotion in them.
This is a decent image, it's just lacks something to put it over the top.