I rarely have a problem with the other guy being able to physically work the camera. Unless the guy is a real dunce (and then I wouldn't hand it to him anyway) it's pretty straightforward.
However, they can't compose a picture for shi... er, beans. The rule of thirds, it seems, means "cut the top third of the head off".
If the thing has a zoom, it's always under or over used- for a portrait, they zoom way out, so as to get the entire majestic vista including the side of the garage, the trash cans, the neighbors' hedge and the corner of the minivan. For posterity, presumably. Either that or it's zoomed all the way in, framing everything from the middle of your lower lip to just above the eyebrows, all in scintillating detail that makes you want to start investing in better skin-care products.
If there's two people standing together, it seems the impromptu photographer centers the image on whichever one he or she either likes better or knows better. Why is that guy standing off to the side, missing most of his left shoulder?
Then there's the short guys or kids that insist on taking the picture. Yeah, I was looking for a low-angle portrait. See that empty sky? That's a high-resolution image of the airpace over the Grand Canyon.
Or they can't hold it level. Why is the ocean going uphill? Why is the Leaning Tower actually vertical?
Don't get me started. 
Doc.