Conference champions should get the auto bids. Conference tourneys are for money. Think of all the great teams from 1 bid Leagues that had one hiccup in their championship game, and some other crappy team got in instead. The whole regular season is pointless for those conferences.
And when it happens in a bigger conference those undeserving teams steal a bid from an at large team from somewhere else in the NCAA that are often better and more deserving.
But the biggest reason this is good in the WCC is for strength of schedule. Playing crappy WCC teams again in the tourney just hurts the top dogs NET ranking