I agree
Data has to be stored somewhere and on something. If I was building a massive datacenter would I buy all expensive flash disks to put in my array or would I go for the cheap SATA drives? Until the price of flash and other upcoming fast access stoarge devices comes down, you will not see a big shift to it.
I, personally, am planning to buy a new SAN for the office and put flash drives into it for frequently accessed data and SCSI drives for live data but lesser or archived data can rot on SATA for years for all I care.