The root of this controversy is probably the high-end Chromebook Pixel C introduced in September. The Pixel C runs Android Marshmallow 6.0 and created a hybrid third use case, combining the unique features of both Android and Chrome OS into a superset of both.
Here are the eight things that will help you understand the controversy for yourself.
Converging Android and Chrome OS into one OS that supersedes both is easier said than done. The hardware is converging much more quickly than the use case and the software. Chromebooks, embedded devices, and smartphones all are used differently. The superset represented by the Pixel C is very attractive, but why drag the overhead of all the underlying Chrome OS and Android software to an interactive Chrome kiosk, a Chrome control panel, or a Chromebook used in an environment where just a browser meets all the requirements