Hello there !
As the title says, I would like to know why Collider derives from Component instead of Behaviour, since it has an enabled property. Isn’t the difference between Component and Behaviour the fact that a Component is not disableable while a Behaviour is ? Or did I misunderstand API’s architecture ?
Thanks in advance for your answers 
(yeah, that question is useless, I’m just being curious
It’s more a conceptual thing. A Behaviour is usually an active component that controls the Behaviour of the GameObject. A Collider is a passive Component. It doesn’t do anything. It’s just “used” by other active Components like the Rigidbody.
I know the Rigidbody isn’t a Behaviour either, but i guess it was a compromise since a Physics object can’t really be disabled. Even as kinematic Rigidbody it’s still an active component.
The class hierarchy might not be perfect, but i guess behind every decision they made there’s at least some kind of reason / sense 