Why should we be excited by a $30 1TGB drive today? 5 years ago I was paying $50 for 2TB drives.
That's my point. Development has slowed on higher capacity platter drives for a number of reasons... our demand as consumers might have slowed, but the "cloud" continues to grow and demand storage, but cloud providers are willing to spend too much for enterprise-grade storage they need. Technology is certainly a stumbling block, but they've been talking about these advances for many years. The main reason for the delays and jacked up pricing was plain and simple greed. The Thai floods were a godsend to the industry, which saw prices plummet below $0.025/GB - and suddenly, they were able to charge 3 times the price for all the drives they had stockpiled (not unlike the Sumitomo explosion back in '94 that drove RAM prices to 5 times their previous prices overnight - when the epoxy resin Sumitomo made was in plentiful stock supplies and never was short)
So platter drive makers have sat back and reaped profits, instead of staying ahead of the SSD price/performance/capacity changes. By 2020, those lines will have crossed. We now see "Enterprise" class SSDs, so capacities WILL continue to rise, even if most consumers only need a 1TB or 2TB drive on their PC. Server farms running only SSDs will be a thing in the future. They may even end up being more durable than platter drives by 2020, and that will make it an easy choice for cloud providers, even if it comes with a slight price premium.