Usually the fairness that people seek in these situations is just the desire to dump the unfairness on someone else. E.g. the demand to extend the discount to 3-month old purchases ignores the fact that the people who bought a car 3 months and 1 day ago will feel more upset and wronged.

More wronged? Maybe a couple very unreasonable people. In general I doubt it.

Also you can handle that with a staggered discount.

More meaning they would have felt wronged even before that.

In general I agree that it’s unreasonable. Discounts happen, prices change, we can’t always time purchases perfectly.

And as Musk pointed out, back in the days when Tesla raised prices, no customer who got the prior low price volunteered to send Tesla a check for the difference.

That's not a good argument.

The general expectation is that customers should know when lowered prices start and end, and be able to take advantage of them.

Not that they want the newest price.

I know it's not. I was being tongue-in-cheek.

I got a Model Y three months ago.

Je ne regrette rien.

There's also no advertising relationships that would dissuade anyone from bashing. This is not to say that Tesla doesn't deserve the bashing (it does).