The Better Mousetrap rarely wins
I tend to agree with Mellor.
The external storage market is optimizing along the guardrails:
One path: Arrays for transactional workloads, with the purchase led by $/IOPS and solution integration. This is NVME, AFA, and memory-based solutions.
The other path: Storage for persisting unstructured data cheaply and efficiently. This would be scale-out NAS and RESTful object.
And the middle - all the run-of-the-mill enterprise apps running in ESX - will be slowly captured by VSAN/Hyperconverged (including HDFS), especially as VmWare and MSFT duke it out for the full storage stack, blowing away the remaining mid-range array vendors in the process.
Yes Tintri and Pure make a great mousetrap, but in a maturing market, that can never be relied on as the ticket to survival. Customers not going to VSAN/HC will take the low-risk path of EMC, HP, IBM because their products are "good enough". Pure and Tintri, in an effort to show positive cash flow, will eventually have to cut back on cost-of-sales, and then getting the n+1 customer gets harder and harder.