> if you allow an API over HTTP, you're allowing that API to any attacker.

In the scenario I described you're doing that only after the user has explicitly opted in on a case by case basis, and you're forcing a per-session nag on them in order to coerce mainstream website operators to adopt the secure default.

At that point it's functionally slightly more obtuse than adding an exception for a certificate (because those are persistent). Rejecting the latter on the basis of security is adopting a position that no amount of user discretion is acceptable. At least personally I'm comfortable disagreeing with that.

More generally, I support secure defaults but almost invariably disagree with disallowing users to shoot themselves in the foot. As an example, I expect a stern warning if I attempt to uninstall my kernel but I also expect the software on my device to do exactly what I tell it to 100% of the time regardless of what the developers might have thought was best for me.

> More generally, I support secure defaults but almost invariably disagree with disallowing users to shoot themselves in the foot.

I agree with this. But also, there is a strong degree to which users will go track down ways (or follow random instructions) to shoot themselves in the foot if some site they care about says "do this so we can function!". I do think, in cases where there's value in collectively pushing for better defaults, it's sometimes OK for the "I can always make my device do exactly what I tell it to do" escape hatch to be "download the source and change it yourself". Not every escape hatch gets a setting, because not every escape hatch is supported.