"Can't" can be misleading. First, it might imply there are techniques or genres/sub-genres that are beyond the reach of the player regardless of the amount of desire or the amount of practice. I'm still optimistic enough (or naïve enough ;) ) to not believe that. On the other hand, "can't" could be a reference to a point in time..."can't" do it now 'cause the effort hasn't been made. That's much more acceptable to me and ultimately leads to choices between genres and techniques. Some just don't care that much for shredding or fast playing. I've read there are the same pro and con arguments about fast playing in jazz. That all comes down to personal taste. Shoot! Rockradio.com lists nearly 40 rock sub-genres (just rock!) and some of my favorites aren't on the list. :rolleyes:

Practice to play what you want to play but don't expect everyone to want to listen to it. Or, practice to play what your audience wants to hear. Or both. :D