Not everyone can pronounce the word wiphala, even though it is as Bolivian as potatoes. The puff of air that is supposed to follow the p works for us English speakers (we-paula) and is a must in Aymara and Quechua, but is just not something Spanish speakers can manage without a lot of training. The aspirated p, on their tongues comes out like either a naked p, with no burst of air, or an f. In either case it sounds wrong and foreign.