I entirely agree. but, where as you can go straight from fiat to bitcoin (if you jump through enough hoops), you can't do anything of the sort with PIVX or really any other. Making bitcoin the only one of the bunch that can interact with the pre-existing (and importantly, Massive) monetary structures. There is no way to get the other coins ... that makes the relationship between PIVX and BTC very similar to the relationship between gold and a fiat currency. PIVX is the fiat here.