VMAX (Symmetrix) has been in stark decline for a long time. Numerous systems have passed it by. The idea that HDS is, or was, its only viable competitor either lacks context or is willfully ignorant.
What we're seeing here is an industry trend over the last 3 years now. The monoliths--specifically EMC, HDS, & IBM--are going the way of the Dinosaur and each one is facing significant challenges with revenue generation.
Customers are saying that "big iron" is either overkill, not flexible enough, or some combination of the two. Smaller, simpler, flexible, and more agile systems have broken through and customers have jumped on board. Obviously HPE has benefitted the most with 3PAR but we're not alone. While Pure, Nimble, and a few others might have ugly balance sheets they are growing revenue and have much more credible 'mindshare' than the monoliths do with Flash.