Don't debate this guy on his terms. He is trying to say that bike should not be vehicles. The truth is that bikes are vehicles because the LAW makes them so. Quote the state code to make it clear that bikes are vehicles even if they are viloating the law - just as cars are vehicles regardless of their legal compliance.
Then add a pragraph where you state that better education is needed for both cyclists and motorists to understand the legal and safety requirements of bicycles on the road.
We are already vehicles - period.