cDOT and EF550 are very much All Flash players.
-Disclosure NetApp Employee - Opinions are my own -
1. The All flash array markets is made up of two very different segments, the performance oriented segment (e.g. EF550, 3PAR, Violin, and the old TMS RAMSAN line that IBM bought), and the capacity optimised segment (Pure, Skyera, XtremeIO and All Flash FAS).
2. The vast majority of flash is being deployed in hybrid arrays, or as DAS inside of servers. The market for all flash arrays is still very smal which partially explains violins implosion. At this point in time, each of the vendors you derided probably sell individually more flash per month than the rest of the "All flash" array players combined. All of them are very much "Flash Players", with bigger annual R&D budgets in flash than many of the startups entire VC funding bankroll.
3. The EF540 and EF550 are doing nicely, winning pretty much every head to head performance bake-off I'm aware of vs the "performance oriented" all flash offerings out there for sub 1ms consistent price-performance. Put it up against a capacity optimised array with built in dedup/compresson and it simply blows them out of the water. If inline dedup is super-important to you, then combine it with something like Atlantis and you'd be surprised at how good the result is in terms of $/GB and $/IOP, or you can opt for an integrated offering like the All flash FAS.
4. While an all flash FAS isn't as fast as a performance optimised AFA like the EF540/EF550, its still very fast indeed, certainly fast enough to compete with other capacity optimised all flash arrays, which is partly why it beat out XtremeIO.