I've never been paid to hit home runs at the major league level (no, really), but I can imagine that had I been, a high wall might get in my head. I might even make unconcious adjustments in my swing (swinging a little harder or finishing a little higher) to compensate.
But I would disagree to some extent with the "at any level" comment. I've seen too many younger players fail miserably trying to hit the ball "up" on fields with a short porch. Of course some others get HR's in place of fly outs, but I don't think it automatically makes you better.