I've read a couple comments here and there about Joe not caring about acting and/or the show, and I just don't know how you can come to that conclusion

I agree completely with this. In fact, I've often been delighted by how much JF's comments (I don't want to call them "complaints") about the show echo ours, e.g. his wish for more Sheppard backstory, his misgivings about regular contact with Earth... He's obviously very invested in the show.