Yes, sometimes there is something that puts you on edge about people eating standing up when they could sit. It's just...slightly stressful, although I can't put my finger on why.
But people being forced to do it takes it to another level...
I worked in a school which had gone from 4-form entry to 8-form entry. It was on a small, crowded site and the whole thing seemed to have been badly planned and implemented.
Students and staff had to eat their lunch (outdoors, in all weathers) out of cardboard boxes while walking around the central courtyard (it was a secondary, so perhaps 'playground' is the wrong word). It looked awful. I felt sorry for all of them, and it was particularly undignified for the staff.
The French have always thought the English uncivilised for the way we fail to prioritise meals as being important to well-being and quality of life, and I really saw this point of view. It just looked uncivilised - that's the only way I can describe it. They all just shovelled their food in using their fingers as fast as possible and then chucked the box away, sometimes in a bin, often not.
A really gross 'feeding time at the zoo' vibe which I'm sure taught the kids a really negative lesson on many levels.