even with a freaking rondel dagger you can rightswing someone without being in kicking reach
This isn't true. Both players with the same weight and the same agility, if one guy has a <50 reach weapon and the other actually moves, either the short weapon guy always misses or just doesn't attack, either he is vulnerable to kicks. With a short weapon and some uncertainty on where your enemy will be in the near future (because he is movign too), you are forced to make provisions and end up slightly closer to the enemy than your max reach. The only way to effectively counter kicks with short weapons is to facehug and turn around your enemy very quickly, as landing kicks in such a situation can be difficult.
Most people don't kick with the intent of being hit while they kick anyway so this wouldn't change the game much I think. If kicks are going to be buffed in any way to compensate for that, then just don't do it.