I know it can be tempting to complain about pedestrians if you use MUPS, but whenever you get annoyed, write down what you want to say, then replace walker with cyclist and cyclist with car and see how you would feel about it then.....

It is always the responsibility of the larger/faster party to be aware and careful of the more vulnerable. On the road that means cars need to be aware of cyclists and on a MUP cyclists need to be aware of peds. It doesn't excuse bad behavior and certainly accidents can be caused by clueless walkers, but it does obligate cyclists to slow down and yield to walkers, even if the walkers are not following all of the rules.