Cannot switch gamemode with F3+N, even though I have permission

If I'm not an OP, but have permission for /gamemode creative (which it runs if I am an OP), the client won't try to switch gamemode. While being OP and having permission for the command is the same on vanilla servers, it isn't on others, and I think it'd make more sense for it to let the server check if the player has permission, rather than the client asssuming it.