I struggle to find something more obnoxious than incorrectly employed formal logic.

There is no contradiction. The intersection of “native-sounding English” and “(English with) no grammatical errors” is not empty. So it’s actually perfectly possible to meet both criteria.

It also wouldn’t be a logical contradiction even if it wasn’t possible, since contradictions are conflicts of arguments that rely on different propositions being true, not the valuation of the actual propositions.

Your solution is worse.

As is, it is the responsibility of the content provider to make sure that they are distributing only to people who are legally allowed to have it.

With age-verification the user has to prove that they are allowed to access the content, then the site can distribute it to them.

Your approach is to distribute the content by default and only deny it to ChildDevices. In order for this to work at all, you have to mandate that children can only use ChildDevices. This is soooo much worse than simply requiring that adults who want to see certain content have to prove that they can legally access it. If adults have reservations about providing ID for pornography, the loss of such content seems to be much less than denying children Internet access. (Although, I’m sure that Lemmings would disagree for obvious reasons).

Bad faith argumentation has nothing to do with honestly presenting your views. I can defend positions I don’t actually hold just fine, an argument doesn’t gain any special properties depending on who makes it. I could even claim that I held these beliefs and it would have no effect. Rather, bad faith argumentation has to do with how you engage with your opponents arguments, not your own. An example of bad faith would be if your opponent said that they liked Germany, and you then spun it into portraying them as a Nazi.