Re: Fair enough, but...
"Perhaps it's also time they were required to carry insurance?"
The case for compulsory insurance is that motorists can and do kill people when it goes pear-shaped. That's also the reason that only third-party insurance is compulsory.
Cyclists tend not to kill people when they get it wrong, in the same way that pedestrians don't. I'm sure you can find counter-examples of both, but the numbers are so insignificant that society doesn't feel there is a problem to be addressed.