"What makes you think they don't p*ss on the allotments too? :0)"

What makes you think the allotment holders don't, as well? As organic gardeners like Bob Flowerdew will tell you, urine is the best compost activator you can get. It works - and it's no worse than putting manure on your veg patch.

"someone would have to take responsibility to water every patch, esp. through the summer or it would all die"

Not necessarily. I seldom water any of my vegentables, with the possible exception of tomatoes and chillis, and I get good crops.