If websites implement this, it will effectively make building a web search engine impossible for new entrants. The current players can whitelist/attest their own clients while categorizing every other scraping clients as bots.
If not for other reasons, I can't see how Google a search company can be allowed to push something that can kill competition using its market dominance in other areas like browsers.
I hadn't really considered this. In a roundabout way, is there a process for this to be rejected on grounds of "fair use" limitations?