Culturally speaking: Why do some people find it so hard to tip their Delivery guy?

I never understood why people find it so hard to tip the delivery guy....I always tip my delivery guy..I think its wrong not to. Maybe because Im just considerate but after I seen this 80 year old chinese lady deliver my food I made an oath to always tip them. I don't tip the ones who try to screw me over though. Actually I even confront them like I know how much it costs, why you tryna play me? ........Ya knowCulturally speaking: Why do some people find it so hard to tip their Delivery guy?
Because a few years back anthrax was being delivered throught the mail. I wouldn't tip my killerCulturally speaking: Why do some people find it so hard to tip their Delivery guy?
Where I'm from its not common to tip the delivery guy its more common to tip waitresses and waiters at restaurants but I've never heard of anybody tipping the delivery guy in London.Culturally speaking: Why do some people find it so hard to tip their Delivery guy?
guess who probably doesn't? maybe the ones who are notorious for not tipping in restaurants?
Cool story bro