Agreed! If I had to take a guess, its a Risk vs Reward game so-to-speak. Your ISP doesn't really have anything to lose by complying, but Cloudflare's whole business revolves around reputation (something most ISPs clearly don't care about unfortunately) along with being a massive CDN. To them, the risk of having their reputation sullied by someone going "I don't like this" and taking down a potentially paying customer's site makes it worthwhile fighting the legal battles that could come out of not complying with a takedown request.

Just guessing of course, but it would somewhat make sense.