I could see it with C-ABS like you say or maybe a 700lb upright street barge like a Harley, But a mechanical on 370 lb bike would lock up the rears regularly creating a slide out hazard I would think.. I'm definitely not a fan of the idea, then again I'm not sure I like abs on a bike cause it increases the stopping distance, but on the other hand will help keep you from sliding out, or front flip in an emergency stopping situation.There used to be some bikes in the past with a mechanical synchronization of front and rear brake, but it was a technology that didn't evolve.
Now, Honda has some bikes with C-ABS (C is for combined) which is an electronic rear/front linkage of the brakes. I don't know how good or bad it is.
The thing is the most of the braking power is on the front tire, so it looks like a good abs front brake is the way to go.