It is great that you care and believe me, this behavior happens at every MUP in the U.S. There are 10 percenters that ruin a good thing for everyone, you could add 100 new laws and regulations for the path and those 10 percenters will still be out there. In fact, if you get the bikes banned on the MUP those office racers will be still doing what they do on your MUP, the current laws don't stop them.