alt Hacker NewsQuery strings existed before CGI did, and the way they're defined to be filled in from web forms is quite useful; I wouldn't want to need Javascript to fit that into path format. There's nothing wrong about having things decided by the server; I don't get that part of your argument at all.
Maybe dumb question: how does the server “decide” anything other than what file to serve? Today we have many choices but back in the day CGI was the first standard way to do it.
So yes query parameters existed before CGI but to use them you had to hack your server to do something with them (iirc NCSA web servers had some magic hacks for queries). CGI drove standardization.