Because now you will be going via insurance process where drivers rates will be reviewed and adjusted. Hitting an insured 'bike' now introduces an actual process where parties at fault will end up paying.
It's not going to be 'Oh I'm fully insured, registered and have a license. Who is this cyclist again?'.
It's not going to be 'Oh I'm fully insured, registered and have a license. Who is this cyclist again?'.