It's a pretty easy game to win as the blocker. If you receive too many 404s against pages that don't exist, just ban the IP for a month. Actually got the idea from a hackernews comment too. Also thinking that if you crawl too many pages you should get banned as well.

There's no point in playing tug of war against unethical actors, just ban them and be done with it.

I don't think it's an uncommon opinion to behave this way either, nor are the crawlers users I want to help in any capacity either.