there are the folks crying on the street begging for any money to get food, but don't want food directly even if you've already bought it for them with no strings attached
Most homeless people have serious health problems. Dietary restrictions are the norm for people with serious health problems.
No, you aren't doing a diabetic or someone with life-threatening allergies a favor to act like they should eat whatever the hell a random stranger bought them because "beggars can't be choosers."
Plus, you know, people have preferences. Acting like you should stop having food preferences because you are dirt poor is straight up classism of the worst kind.