So it's ok to think of other path users as tw*ts and expect them to get out of the way is it? That seems to me as the mindset of a selfish d1ck. Translate it to the road, and imagine the pedestrian is a cyclist and the cyclist is a motorist. We all have to accept each other on whatever right of way we use, be it road, shared path, bridleway. You cant have your cake and eat it, however much you wish so.
It's ok to THINK it; but it's not ok to say it out loud. Don't try to tell me that the actions of other people in whatever walk of life don't annoy you on a daily basis. Of course they do! But you just get on with it; accept it for what it is and deal with it, without offending anyone by thinking out loud....
Translate the circumstances to the road as you suggest... If I am in the car or on the bike and I see a big truck that needs more space on the road than I do, then I will do my best to give it that space. Even if it does not have any legal right of way over me. Again, it comes down to common sense and manners.
I was not suggesting that it is ok to go tearing along shared paths at speed and expect people to dive off the path. The picture I have in my mind is my usual ride on a sustrans disused railway path. Narrow, with shrubbery on both sides. Not much traffic either bicycles or pedetrians; so it is usually fine to make progress. As I approach the group of people coming towards me, I slow down and cover the brakes. They see me, but make no effort to step aside (not asking too much am I?). Only when I am right in front of them does it cross their dopey minds that I have nowhere else to go but the path. They then grudgingly move aside to let me through. By which time I have stopped. This happens on a regular basis.
The alternative suggested by someone, to stay off the path and use the road. Perhaps you cycle in leafy suburbia, but in this case the alternative road is a main trunk road. Single carriageway carrying heavy traffic. Perhaps that is the reason why the Sustrans path was created? I would rather incur the wrath of selfish walkers than get flattened by a truck; thanks.