There is a primary school at the end of my road, and some the children there do some kind of cycling proficiency. However, at the start of the session, they send all the children down to the end of the cul-de-sac, and they clump in the road on the junction. TBH, I think whoever is supervising the children has a duty of care to make sure they stop in a safer place, as some road users are impatient.
Adults pedestrians should take some responsibility for themselves though. I saw someone out for a jog on a busy (dual carraigeway) A-road the other day, which seemed a bit mental. It might be legal, but it definately isn't safe.
Equally, on the same road, I had to negotiate a hurse driving along at around 10mph. Most cars do 60-70mph on that section of road, so it was a real hazard.
Basically, I think drivers do have a duty to behave safely and expect the unexpected. However, as a pedestrian, you should look after your own safety and that of any children you are with. Sometimes drivers make mistakes, and ultimately you will come off worse.
I do think a lot of drivers don't actually know the highway code well enough, though.