Well as someone who spent years delivering pizzas to colleges, I can tell you, generally speaking a run to the college campus address was often a poor or non existent tip, and a lot of BS to deal with.
I worked for the Dominos in Oakland section of Pittsburgh back in college as one of multiple jobs I held while going to school.
At that time Dominos had a deal where you could trade in your school voucher money for pizza’s with CMU, and I want to say Pitt as well, but it was a long time ago, so I may be incorrect.
The kids would get something like $3.77 or something per meal they could credit to a purchase, so they would pool their meals and order some ridiculously large order, and they could use the money to tip as well, but often tip was nominal at best, particularly considering the size of the orders and nonsense around the paperwork needed to be signed to get paid. So I wouldn’t write too much in a deliver guy on campus not being the friendliest. Number of drunk arseholes I had to deal with during those years from various frats, and dorms was countless.
The other thing I learned back then was, the bigger and fancier the house, the lousier (on average) was the tip.
One time I delivered an order, to what was easily a multimillion dollar mansion.. A very well dressed woman answered the door, paid me and they tried to act superior, telling me keep the change... the change was literally .27. I said, no, made them wait for me to dig .27 out of my pocket, and I told them “Clearly you need this more than I do” and walked away. She called the store indignant, in fact my manager was on the phone with her when I walked back into the store... he waved me over, and asked me what happened... and I told him... after hearing my side, he politely told the woman, she was not allowed to order from the store again.. and he gave me a token “don’t do that again”, which was all for show.. and to his credit he did add the address to the banned list.
If you are finding Poppa John’s bland (its a chain, so none of them are too crazy), I would question highly if your franchisee is “cutting the sauce”. This I have seen and heard about frequently, especially if the franchise is owned/run by folks who weren’t born in the US. From a chain perspective, they are one of the more flavorful pies in my experience, when the pies are actually made properly and to spec.
Completely agree about delivering to colleges. My record for one night was 54 deliveries, mostly triples and quads to the dorms.
My observations, in about 17 1/2 years with Domino's, on and off, 5 stores in 2 states. Friday night is the worst for tips, like you said the bigger the house the smaller the tip, and the worse the weather the lower the tip.