Dear dip shit car drivers . Why do ye speed up when motorbikers are passing ye out?

I DON'T do this, but I have seen more than my share of both bad bikers and bad drivers. It's mind boggling to me. FWIW, the bad drivers that speed up when the bikers are trying to pass are likely to do it when other drivers try to pass as well. Less dangerous for us, but bad drivers are bad drivers all the way around, more or less.