Well there are a lot of people out there who want to learn Kyokushin but don't have any desire to do knockdown due to any number of reason - so Clicker enables them to compete, to test themselves on the mat.
I can honestly say I don't recall ever being caught holding back a technique in a knockdown bought (won my last tourney, stopping the guys in both rounds 1 & 2) or being disqualified for excessive contact in Clicker - my mind can separate the two just as it knows what is kata or kihon and I always spend weeks doing event specific training - I mean no disrespect but I think the holding back thing is a myth generally held by people who have never done both.
One last benefit is when I am training for knockdown I can go full power at the lower levels but control my head kicks to just enough to know what could have been
, this way I know they work in a particular situation without sparking out my sparing partners
