This. Pretty much explains why SSD remain a marginalised technology.
That, and hard drives are tried and tested technology that has proven to be very reliable - and for most people who like myself use desktops, they won't see any considerable advantage for me to make the switch to SSD.
I have no doubt they are better - But it's that Betamax vs. VHS chicken and egg situation. Betamax offered superior picture quality; but it came at a cost. Only a small handful of manufacturers sold Betamax. VHS was sold to any and every manufacturer who wanted to make a quick buck - and the quality difference was negligable to the consumer.