My father-in-law is a pretty big person, and would just sit there in lines talking on the phone, holding for 10+ of us.
I was kind of in shock the first time he did it and my wife was like, "see, let's cut in, my dad saved us a spot." I would sometimes refuse, out of courtesy, and then after a while I became a part of the problem because I realized I would never see the rest of those people again, so I could suffer the shame for a brief moment. Bad logic, I know, but hey, he saved the spot. I don't agree with it. I marvel with those who feel completely justified in doing that.
It reminds me of the long line of people at Disneyland in the handicapped line. I think a good 95% of them qualify as severely obese, and maybe even also over 60, a brutal combo. I just can't see myself wanting to go to Disneyland if I can't be bothered to walk more than 50 feet without collapsing.
Now, young kids in wheelchairs, or people with actual disabilities, I get it. Just the optics of the obese people in the handicap lines is a bit off.