Forrest is sick, his personality can be a little off but he probably hangs out with a bunch of dudes who are just like him so he rarely notices. I do find it weird how he can be so down with theotis but not realize while theo is really sick he didn't get where he is solely from ripping, theo seems like the nicest dude in america.
Also for COTG being nice doesn't equal dick riding in every scenario, or even the vast majority of scenarios. However being too nice for the sake of acceptance can be dick riding (though I personally don't think that everyone who is nice is being nice to be accepted, as that would be a jaded worldview).