Credit Card Apps - All in same day

I know this board loves them some credit card talk. I've always read about credit card "app-o-rama", but never really understood it. I utilize the hell out of cards and points, but never really understood why some play the "apply for 5 cards in a day" game. Browsed through the Flyertalk Forums but they were more discussing the game than why.

Is it to make a point grab and be able to churn them faster, or because they don't think their credit will allow them to be approved for so many cards when they otherwise don't? My wife or I apply for a new card every 3-5 months. Max the bonuses or benchmarks for extra bonuses and move on to another card. Cancel most at 1 year mark unless annual fee is waived or card gives enough annual reward to justify keeping.

Anybody do this? Success?