I think they misunderstand what people are complaining about.
People don't want discounts for one person while another gets overcharged. It's a good thing if it threatens discounts. Everyone wants to pay the same price for the same thing.
Discounts can be annoying even when they're "fair"
It's annoying when something was discounted yesterday, and now you have to pay more. Or when you just bought something last week, but now you could have saved a bunch because it's some arbitrary special day. Temporary discounts of any kind are inherently unfair and manipulative.