Steam isn't the guilty party in this nonsensical bullshit, Ubisoft is. Steam allows you to list titles with zero DRM, zero Steamworks integration, or zero online components just fine.
Valve has enormous power and uses it often, even at one point de-listing our entire catalog without warning because we had an additional asset in a game which was granted based on region. (and we got blamed in the media for it).
Ubisoft games are still on Steam despite this, though the big publishers despise this amount of power, and sometimes valve does come across as bullying when you’re on the receiving end.
Those ubi points exist to give people the discounts we aren't allowed to directly give because of Steam licensing terms. :D
The fact they even exist is a symptom of what I'm talking about.
(also: I never worked on uPlay, I worked in the same building)
So they might not be the guilty party, but they are sure not innocent. They are taking the cut of the money. It better be going towards protecting me. If they are not protecting me from bad actors then why am I using Steam?
If Steam is legally required to do that, their contracts with developers will inevitably have the same clauses about refunds if you disable the product.