@lordofthedance1 could be because Caltech noticed other qualities that were a lot more important to them (actual demonstrated deep interest in the subject you applied for) and maybe the Pomona essay was not exactly what they were looking for? At such low acceptance rate colleges, the difference between an admitted and a wait listed person is quite minute. Shrug your shoulders and don’t over think the discrepancy. Also if all colleges recruited everyone similarly, only the top kids would get into all the top colleges. That hardly ever happens. Colleges also make judgement calls based on personality traits highlighted.