I'm a TKD student, participate in tournaments and compete this way. I have the trophies and medals to prove that you can spar competitively with your hands up, block more effectively and save yourself from a knockout head kick. The lack of people punching and not guarding just makes it easier for me to score on them when I drill into them or step INTO their round kick and backfist them in the chest. Sadly though, many many punches don't get counted because: a) bias on the judges for the WTF hands down, flashy kicks style and b) they happen at closer range so they are not looking enough even when you knock them on their butt by it. BUT at least I know I scored and for me the real point of competition is trying my self defense skills out in a safe way against a fast live opponent.