> If you are serving web pages, you are soliciting GET requests

So what's the solution? How do I host a website that welcomes human visitors, but rejects all scrapers?

There is no mechanism! The best I can do is a cat-and-mouse arms race where I try to detect the traffic I don't want, and block it, while the people generating the traffic keep getting more sophisticated about hiding from my detection.

No, putting up a paywall is not a reasonable response to this.

> The question is are you expressing a preference on etiquette versus a hard rule that must be followed.

Well, there really aren't any hard rules that must be followed, because there are no enforcement mechanisms outside of going nuclear (requiring login). Everything is etiquette. And I agree that robots.txt is also etiquette, and it is super messed up that we tolerate "AI" companies stomping all over that etiquette.

Do we maybe want laws that say everyone must respect robots.txt? Maybe? But then people will just move their scrapers to a jurisdiction without those laws. And I'm sure someone could make the argument that robots.txt doesn't apply to them because they spoofed a browser user-agent (or another user-agent that a site explicitly allows). So perhaps we have a new mechanism, or new laws, or new... something.

But this all just highlights the point I'm making here: there is no reasonable mechanism (no, login pages and http auth don't count) for site owners to restrict access to their site based on these sorts of criteria. And that's a problem.