Re: in response
1. It's function over form - some information is better displayed on a circular format, whilst other info - text especially - works better in a square or rectangular frame. Jony Ive considers his (circular) Omega Speedmaster the epitome of good design, but the Apple Watch is designed to show different forms of information besides just time.
The majority of Android can Wear watches are just aping the already dubious form of 44mm fashion analogue watches. That's not to say I think circular smartwatch are a dead end - rotating a bezel is a good form of human input.