Apparently they modified their terms in April or so, if I recall correctly, to allow this, and I guess most publishers/developers have accepted those terms without really thinking about it too much. Either way, I'm 99% certain their terms allow this kind of stuff since some date 'well' in the past.

The plot continues:

When I read Riccitiello's bio, I couldn't help to think about Steve Job's lost interview. Watch it from 25:51 [there should be a timestamp in the link below], for about 3-ish minutes 

and then check his Wiki page under "Career" [first sentence]

https://en.wikipedia.org/wiki/John_Riccitiello

I saw Pepsico in the video and the wiki and just..

I gotta know, how did you manage to make that connection with the lost interview?. The timing matches up near perfectly with John's career history. 

So what is their justification for doing this on a per install basis? Instead of copies sold?
The developer/publisher is not getting more revenue because I un-installed and then re-installed their game again, so I don't get the idea behind this.

Apparently, according to Unity, console+PC isn't as important to them rev-wise compared to mobile:

I get that mobile gaming>Console+PC gaming in terms of revenue, but even seeing an engine maker acting this way towards the two platforms is not helping. It's like a bunch of boomers are still on this warped tirade of "console/POC gaming is dead/dying".

Do they seriously think that mobile gaming companies won't also simply shift their unity engine to another one after the deal they announced ?

It'll be fun to review how this new policy will have affected them after a full year of this idiocy

For some reason they seem somewhat confident that mobile devs will still rely heavily on ads paying for the fees, and that they see consoles/pc as the ones not to care about if they leave, but there is nothing to stop mobile devs from doing the same and simply pulling away from Unity.

It's just daft that an engine maker views two thirds of it's consumer base as "pointless/non important", when you consider just how many games come out on both platforms using their engine, and the uproar this has caused and erupted from devs on those two platforms (if this was from mobile devs only, we'd know about it by now, but this mostly stems from those making games for console/PC). 

Yeah, this policy hurts mobile developers more than anyone.  So many of those games are free to install.  There is a good chance we see games taken down off of stores before this goes into effect.

Unity finally apologize and say they'll be "making changes" to the policy:

We have heard you. We apologize for the confusion and angst the runtime fee policy we announced on Tuesday caused. We are listening, talking to our team members, community, customers, and partners, and will be making changes to the policy. We will share an update in a couple of…

— Unity (@unity) September 17, 2023

Hopefully devs keep the pressure on them and they walk back its nastier components entirely.