Where I live it costs extra to get the pizza/food delivered. Doesn't that money go to the delivery person?
I know around here they make it a point of saying "delivery fees do not go to the driver". I assume it goes to maintaining the vehicles and related insurance.
I have no problem tipping reasonably; they make less money than I do and are doing me a favour making and/or bringing me dinner so I don't have to cook it, or go out and get it. Laziness fee, I call it
I guess it helps that I have been very poor before (and I think my father actually was a pizza delivery guy at one point, come to think of it), so I don't mind being a bit generous with what I have now that I am doing better. If I can't afford a proper tip, I don't eat out or order in.