Because Google has set it up to work. A query parameter is just that it's a parameter for your query. In this case Google has set that parameter to disable AI search results.
I think the only reason they have it and tried this yet is they simply haven't thought about it. I guarantee you if Trump were to read that comment, first of all he wouldn't understand the sarcasm, and would on ironically try and do that.
The PATRIOTS they listen to CAPITALIZE words for NO reason other than keeping their attention on IMPORTANT words. Its what they know.