skybasing

I don't quite understand if skybasing is entirely illegal if you are actively taking part in the game, and not going higher that any of the blocks that are part of the map. Surely you aren't forcing a stalemate, and others could still build up if they wanted?

I have been playing pvp duels a lot recently, and there have been many many players who skybase whenever they get a kit that has blocks to build with. I have asked a moderator on the server about this, and they replied that the skybasing rule applies to the entire server. However, people don't...