I think panhandlers also gauge who they can say things to and get away with it, in my experience.
My daughter was on her way to work (in her nurse’s uniform) when one approached her car window and asked her for money. She was respectful in her response but he started swearing and screaming at her calling her a w (rhymes with shore). I‘ve been at that same corner many times with that guy there and he’s never said anything like that to me. Understandably, it shook her up. (Btw we often have to care for these people in the hospital which can also be scary.)
A couple of months ago I stopped in a gas station on my way to work. There was a young guy by the door asking people to buy him a Coke. I happened to make eye contact with him as he approached me. I bought him a Coke and handed it to him as I went back to my car. I see him there all the time, day and night, so I’m sure he gets plenty of Cokes or whatever he asks for since he stays there long enough, just as the guy in the OP also probably gets plenty of burgers, too.
Like a pp, I have also bought people food and had them get mad. One guy angrily took the bag from me then went over to a nearby car and tried to sell it. Clearly he wanted cash, not food. (There are all kinds of food banks nearby and I regularly see volunteers delivering food to their nearby encampments.) Like so many other societal problems, there have not been any easy solutions to dealing with this, but I see it as a matter of public safety. Arrests have been made in this area for human trafficking, assaults and stabbings and shootings, not to mention so many who are addicted and disease-ridden. They‘ve also found that they’re from all over the place, not just the city, so one approach is that they’re trying to involve agencies from other parts of the state to help curb the problem. Several months ago they cleared out the whole encampment, even providing housing (as well as services), yet slowly, many are coming back. They prefer to live on their own terms and not having others tell them what to do, even if it’s on a tent on the sidewalk rather than an actual home.