I'd love to pretend to be surprised about this but I'm not. I'd quite like to get on my high horse about it but given how much the keyboard for the Surface Pro I am typing this on cost, I can't really. However deliberately crippling a standard is the sort of thing MS have been slated for many times over the years, with plenty of justification. Anyone with enough disposable income to buy an Apple Watch is likely to want the matching charging plate, but the fact it won't charge anything else is pretty poor.
As much as Qi is supposed to be a standard my Lumia 925 won't charge on the pad I use for my Nexus 7, although the Nexus 7 will charge on the Nokia charging pad.