Saving a fellow human from paying a substantial sum of money for something they can get for free seems reason enough.

It's not about denying anyone revenue. The goal is to make easily accessible artwork that apparently has enough value to be sold commercially.

Getty is very litigious about "their" images, even when they seemingly don't own them, or even have the rights to sell them.

> Is the purpose that people find the wikimedia image instead thus denying getty the revenue?

Yes.