A match "mode" is more or less a collection of different settings. I have added a "match" command, which gives the person who executes it a level 50 login, sets a specified password on the server, and executes a matchmode config file (admins can tweak this as they desire). The problem with having a single set mode is that it seems everybody has different "standards" for how they think a match should be run. A league is pretty much necessary for enforcing those kinds of standards. If a match mode used settings people didn't like, they'd simply not use it, most likely.