I always thought hard drives break easier than SSD because if you drop a hard drive on a hard floor, or there is a large earthquake while a PC is ON, the shock could break the motors, disks, and mechanical parts inside a drive.
I'm not sure if many average computer buyers know the difference between SSD and hard drives, and just buy what is cheapest, and fastest for the price. I'm sure if companies advertise the speed and performance of a SSD better more people will buy it like how people buy computers with 16GB of RAM, a Quad-core CPU, but they mainly use their computer for MS Word, web browsing, and other everyday tasks.
The Macbook Air is one of Apple best selling laptops, and the Macbook Air uses a 128GB SSD drive instead of hard drive, so I think a lot of Mac people just buy what is cheapest with the Mac operating system they want to use, and not spend thousands more for a Macbook Pro, iMac, or Mac Pro.
The Samsung Chromebook with a 16GB SSD for 249.00 US dollares is the best selling laptop on Amazon.
I think if Microsoft came out with a laptop which is $500 or less, and comes with a 64GB SSD, and have specs better than the Macbook Air, many people will buy the laptop by MS with a SSD.