Earlier quoted context omitted.
It's a way of teaching helplessness, while inflating your own ego. That grocery store owner wouldn't want help with picking up the heavy box, because he is an able-bodied man. Doing this for him is belittling him, saying he's not an able-bodied man. It's like receiving unrequested advice or assistance on a project. Having grown up in poverty, been homeless for a summer, walked home past homeless people every day for…
There's a whole lot of projection going in your post - you're far too sure of people's guiding motivations based on a throwaway description of a momentary incident, to the point that you're now accusing another poster of weakening people in their community through willingness to lend a hand. I also recognize that direct charity prevents or delays people from finding a better solution You may claim that, but don't try…
Employ homeless people.
Give a homeless person a break. Maybe just ignore them in their shelter. They must do everything in public, for they rarely have a private space. They can't afford the luxury of choosing which actions others may view.
Learn how communities in your area address the homeless people who live there. Remember that homeless people do still live somewhere. This is not a part of their life they will be proud of, but it's not the end of their life, not a permanent placement.