Yes, you may be segregated from a tipper lorry on that path, but personally I have never had a problem with them,. I find other cyclists far more of a danger to my safety, especially when I will now have then riding head on at me, not just in the same direction.
However, if you look at the bigger picture, it is encouraging motorists to see cycling as something that has no place on the road. This is the concern.
We need to make roads safer for cyclists . Removing cyclists from the road does not do that