What purpose does WOA serve ?

I always wonder what purpose does WOA serve compared to a full blown x86 slate other than the obvious cost benefit. Even cost benefit may not be much because one can buy decent spec'd full blown wintel tablets like Acer w500 for around 500$ even today.

With ivy bridge bringing high performance coupled with great battery efficiency, wintel slates can have atleast 6-7 hours of battery life which is more than enough for most people. Why would anyone want a WOA tablet which is severely limited in apps, completely locked down and has no visible advantage over ipad or android, when they can get a full blown wintel tablet at a slightly higher price?