I think grapple knife servers are still a thing because there is a viable audience for them to be endured. Enough people play them for enough people to host them. It's a direct correlation and as long as people enjoy playing them they will still be around. It doesn't affect you if you don't play them so I don't see why anyone has to complain about them.
Exactly.
I personally enjoy knifing servers, especially grapple knife. I used to play them a lot more, but now I really only play when there are no other good servers up. They're kinda like a last resort, and there's almost always one being hosted.
The map hasn't changed because the map is just fine. Sure, the the designs some people put on them get old and crap, but whenever someone makes a different map for a grapple knife server, it just doesn't work or flow as well, at least in my opinion. So until someone makes a map that is actually better than this one, I see no reason to change what maps are being used.