So let's see...
A non wealthy motorist without insurance hits another non wealthy motorist without insurance and the guy who gets hit incurs huge hospital bills and is maimed for life.
By your logic, it's okay to not have insurance, thus it is not forced. Therefore, both motorists were equally 'okay' in their decision making process. Yet the results clearly are not okay, nor equal, are they?
The result is the uninsured motorist is now
liable for those bills, and probably for the disability. That's both OK, and equal. (Well, equal after the liability is settled.)
Eventually, you could expect that people would be concerned that there is a small chance that an accident, moment of inattention or distraction, or error while operating a large, potentially dangerous machine at high speeds could cause damages that are more than one is willing to risk. Someone with financial experience could seize this opportunity and offer to cover people's risk for a premium.
I think we all agree that insurance is a good thing. We disagree that government should force us to use it.
Singling out car insurance mandates as an argument for forced-government purchases looks good on the surface and is more easily defensible since in the United States the State owns the roads and has laws which require doctors to treat people who are injured regardless of their ability to pay. In the absence of a culture of personal responsibility, its easy to see how these laws exist, and why.
What is unseen are the benefits of a society with individual responsibility which is free from coercion.