See how deranged this line of escalation is? How sick in the soul I would have to be to choose to harm your family to increase the safety of mine? Can you see what kind of world you're building when you advocate this?
This is a pretty bad argument, the extreme doesn't necessarily define the middle. The extreme version of free speech is a world where fraud is legal. The extreme version of fire safety is a building with openings everywhere so there's no need for doors. The extreme version of policing is having cops follow you everywhere, including into your house. You can't just reason like that.
To be fair to your argument, you _are_ talking about a “line of escalation” and an issue with a lot of moral complexity. I’m not even saying you’re wrong, rather just that I think you can’t view it so simply. Do you have kids or a husband or a wife? Could you _really_ put their own lives before strangers, or do you just want to see a world where people give more compassion to their fellow human? Because I want that too; I’m just not willing to sacrifice my loved ones for it.
I wouldn't throw stones, we all live in glass houses. Pedestrians (and cyclists, etc.) could say the exact same thing about car drivers - they're putting their lives at much higher risk by not biking (or using a motorcycle, or public transportation, etc.). Heck, drivers are also endangering pedestrians' children through global warming. If you really tried you could probably name a dozen more examples of ordinary people like yourself putting others at risk for their own benefits.
This isn't to say the parent's decision is great, but that this sort of counterargument isn't all that strong, either.
First of all, this is human nature 101. Secondly, simply owning a large vehicle does not equate to 'harming your family'. Bad/impaired drivers are responsible for that. Any other inanimate objects people shouldn't own because you don't like them? People aren't going to simply put their families in Fiat's with Escalade's on the road to show solidarity with the "we need smaller cars" movement.