Only one time I had that happen. It was on the order of "well, if there's any left when the thru hikers are done you are welcome to it..." I'm not normally a very polite person. Pretty sure you can imagine my response about what the little prick could do with any leftovers.
As long as feeds don't happen on the trail and at a public trailhead or public parking lot that the AT happens to run through, and there is no trash left, I say "What is it for anyone to care about?" If you were going to stop at the trailhead or parking lot, nothing is preventing you. If you were going to stop at the trailhead or PARKING LOT for the scenic view and a hiker feed ruined it for you...well...REALLY? Come on...