Windows 8 has a steep learning curve. On the other hand, even a toddler can use an iPad. My relatives who never used a computer and don't speak English can easily use an iPad too. Same for iPhone vs Lumina 920. WP8 is lame!
toddlers can use IPAD because it is a toy meant for toddlers. I am sure at least 80% of the users are teens and toddlers. MSFT surface pro is designed for office and home and for projects in business school. Of course toddlers can also use, that is the beauty of surface pro.