Surely you jest
> they just want something simple and easy to use for Facebook and on-line shopping etc.
Tablets are actually pretty crummy for online shopping. Tablets do OK with a very limited focus and a very small list of features. Beyond that, tiny screens and the tablet interface fare poorly.
The problem with the PC market is that a 5 year old PC is good enough. They're not like tablets where a year old model seems hopelessly out of date. Even an ancient PC can run circles around current tablets when it comes to pure computation. Plus PCs are much more flexible.
Even as appliances, "tablet hardware" does poorly against 5 year old PCs that were trailing edge hardware even then.