It's not just pennies, it's all coins. In a former life I worked in retail and almost nobody would fish around in their pockets for exact (or even near) change. They'd always hand me bills for their purchase even if they had just completed a transaction and had the coins in their pocket. That was in the 90's, and I still see it happening today, even though I'm no longer in the retail world.
I will never "tap" my debit card as long as I have any legal option. Everyone else can wait for me to exercise my consumer rights, by inputting my PIN, verifying the amount displayed on screen etc.
I don't know what to make of the idea that I'm "not valuing my time" by carefully considering my purchases and caring about security. Or that the seconds I take on this are so important to both myself and others, compared to the time spent browsing the store shelves, getting to and from the place, etc. Heaven forbid I choose the cashier instead of a self check-out this time, and try to strike up a conversation.