I'm thinking a macerator and a sprinkler might be in order. Free grey water for everyone!
In all seriousness though, I try to avoid it but really don't see a problem if it is allowed and doesn't run into another camp site. Also as long as it isn't stewing in the tank for a couple days THEN being dumped.
I haven't done such a thing in my more recent holding-tank days but our first popup had no holding tanks but a spigot to attach a hose to for waste from the sink. I sure as heck laid a hose into a ditch and let it run out. We also cleaned our dishes outside.
I do get that food waste can breed bacteria. A couple things come to mind on that: First, I would not be eating off of the ground that I would dump on. Food drops from trees naturally in addition to the food scattered from the picnic table. I use antibacterial Dawn to wash dishes with. Campgrounds have encouraged watering with grey water for a LONG time and people are not dropping dead of e-coli. Probably because they aren't dragging their hands through the dirt and then eating. You can get some nasty stuff that way whether someone has dumped grey water or not.
I think I read a post a while back where someone wouldn't dump their bathroom sink water because people spit in it. My goodness.