I agree with the lazy people. Service with a smile and all that is important. If the service is bad enough its certainly grounds for no tip.
On a side note, my big pet peeve has always been how most delivery driver's get shafted when it comes to tips. Far too many people tend to think $2 for a $40 meal is a good tip. Or a dollar. Or less than a dollar. Or nothing. I especially hate it when they are all friendly, say thank you, and then don't tip. Like "thank you" is somehow enough. It's a slap in the face. They should tip like they do a server, a percentage. Delivery drivers, if anything do more work, and they have the extra costs of fuel (which not all delivery business reimburse), oil changes, wear and tear, etc.
If a person is to cheap to tip, fine, go pick you damn food up yourself. Unless the person is rude or something like that (I don't usually count late as grounds for not it, because their are variables beyond their control that can cause the delivery to be late), then yeah little to no tip is understandable.
Just one of those things that really oils my blood, since I worked the job (never again), was always friendly and polite (except for two occasions but I won't get into that), but had to deal with this sort of thing, among people who were rude, and other things.
But I digress.