i have zero issues with children... i have a four almost five year old for the love of Christ... however, if i go to one of these places, and i choose to sit in an area designated for adults, it's likely for a reason and that reason is likely to get a break from children...
it's not an unreasonable expectation i don't think.
and kids on my lawn isn't an issue... people walking their dogs and letting them shit in it w/o picking it up is the issue. i've literally had neighbors walk their dogs and seen them shit in my yard whilst they watch, and just walk off... meanwhile, same neighbor, while i'm walking my dog yell at me from the house as we approach (and my dog firmly on the street) "if that dog shits i my yard you better pick it up!'....
to which i've answered "or what MF'r?"
my neighbors are mostly assholes.