As a North American sports fan who did not grow up with Soccer, I'm conflicted about the whole concept of penalty kicks. I really like how soccer really embraces the concept of a tie as a realistic and reasonable outcome: not everything in life is a clear cut win or loss. Ties seem to disgust and almost enrage NA sports fans. Since the NFL has gone to the current overtime rules ties have become exponentially more common and I have a real fear that backlash against the more common tie will lead to the NFL adopting something like the NCAA format, which I dislike.
Of course in a knockout tournament you can't have ties because SOMEONE has to move forward to the next round. But it sucks to see 90+ minutes of game decided on just a small facet of the game itself. I can 't think of any better alternative though.