The benefit is getting a car, or a place to stay, far more easily.

My point isn't that these services are net good (though I do think so). It's that any "net bad" argument that doesn't consider these benefits isn't serious and so discredits its own side.

And if you don't like that, no one is forcing you to use it.

Every driver on the road is a potential uninsured operator. Uber didn't create uninsured drivers. And they require their drivers to be insured. Should we ban all vehicles because they might at some point be uninsured?

Uber got popular in SF even when they only had towncars (which cost more than taxis) simply because their drivers would actually show up. They shouldn't be skimping on insurance, and that's not the only reason they exist.