A FitBit doesn't need to learn from another device. The problem with the watch is you need an expensive phone just so your expensive watch can accomplish its basic features. If you don't have an iPhone, your Watch is gimped from the start.
Fortunately the next Watch is going to be more independent...?
Yes, as the first iPod needed an expensive Mac just to accomplish its most basic features. The Watch, as it stands, is an iPhone accessory.
Expect a more independent and Android-compatible Watch in the future.