Kudos to them for trying.
In thinking this out politically, rather than laws like this specific to bicyclists and pedestrians, I think efforts might be more successful if it included as many road users as possible. An "Unprotected Road Users" proposal that includes motorcyclists--who routinely deal with exactly the same "Didn't see them" BS as cyclists do--would get another lobbying group and demographic on our side. Even better, some kind of "Violation of Right of Way Resulting in Injury or Death" law that includes car drivers and passengers.
It's all about tactics.