Why would anyone buy Surface Pro over Lenovo Yoga 13?

I know...

- "it's Microsoft"

- built quality

...

But... When I have to choose between 13 inch laptop (and tablet) with full physical keboard at 17 mm thick and 10.6 inch tablet with weird keyboard (not really a laptop) at 16,5 to 18,5 mm thick (depends on kind of the keyboard) - why I am supposed to choose the second one?

I will appreciate your input.