I also deliver pizzas

Not really. Time's are tough for everyone. If the customer doesn't want to use a coupon, why not do that? It's not hurting anyone.
Honestly, I'd have to question the intelligence of anyone NOT doing this.

Actually, it hurts the company and the other employees, as some of them may need to be laid off or take a pay cut.

If it hurts the company, they wouldn't be offering the cou...
You know what? It's not worth the trouble to explain it to you. Just keep hold of your entire worldview. It's perfect.