they're both insurance. they are both now mandated. they happen to be insurance for different things, but that's immaterial in the bigger picture.
you seem to think you and some guy who you could hurt (read health bills as well as fixing up the car) having a probable accident is somehow vastly different from a probable trip to the hospital potentially costing you thousands of dollars.
they're the same thing, just slightly different circumstances. just because one involves two parties is again immaterial, they both protect against things which could happen in the future, but aren't guaranteed to happen.