My husband does the same thing, Brain. He throws eggshells, avocado seeds, and whatever else he wants into our yard.
I get all upset and go get it outta the yard, try to reason with him to no avail, then get mad and yell, and all that...
He wants all the natural things to go back into the yard to become compost (yet he has no idea how compost decomposes and I'd have to do the work anyway)... we just don't compost anymore cause I had such issues with it, so now it just looks like food junk lying around the yard.
Recently though he's stopped it. Not sure why. Thank god though.