There to me is clearly a difference between a tip, and asking for money for charity. I don't care for either at retail doing so but do clearly understand the difference.
In the old days occupations that were expected to make a significant amount in tips had a lower minimum wage, and fast food was not one of those. A tip was supposed to be for personalized service. If I order at a counter and someone hands me a bag, to me its no longer personalized service, so I really shouldn't be expected to tip. Having said that I tend to add something to the bill at this point. I usually don't accept their 15, 18 or 20%. I put in a custom tip. Last night I tipped $5 on a $50 counter order. I have succumbed I guess. I loose, they win.
Makes me wish to eat out less though, and I do eat out less now.