Taking cyclists off the road means that drivers will feel that the road is their domain and make cycling more risky
Yet that's exactly what they've done in certain European cities, and cycling has flourished. The thing is that taking cyclists off the road and putting them on bits of old pavement that have been redesignated as cycle paths isn't the right action. The cycle paths have to be so good and connectable that people prefer to use them over the equivalent road route. The national policy has to operate in favour of the more vulnerable.
It's not about lack of space, it's about having the political cojones to reallocate space. MMW is so convenient for helping people get to where they want to go that cyclists and pedestrians use it all the time. The Stenhouse-Broomhouse-EDP path is mostly completely unfit for purpose.