In any case, I think it's more a story about hubris and miscalculation. Even the apology misses the most important fact, which is not necessarily the cost of the change itself, but the demonstration that Unity is willing to change terms AFTER you've shipped software using their engine. That's a massive breach of trust as well as a massive risk. What's preventing them from announcing next September that new installs will incur an even larger cost or that the thresholds will be lowered.
And the obvious fix to that is to put out an announcement saying "Sorry about that, you can trust us, and if you release a game using Unity you can stick with that version of the ToS instead of us being able to foist new terms on you whenever we want forever."
Except.... Unity did that already last time they made company destroying ToS changes, and then just went back on the promise and said they're forcing the new ToS on everyone. So why the hell is anyone supposed to trust whatever apology they put out this time?
https://blog.unity.com/community/updated-terms-of-service-an...
Updated Terms of Service and commitment to being an open platform (2019)
Retroactive TOS changes
When you obtain a version of Unity, and don’t upgrade your project, we think you should be able to stick to that version of the TOS.
In practice, that is only possible if you have access to bug fixes. For this reason, we now allow users to continue to use the TOS for the same major (year-based) version number, including Long Term Stable (LTS) builds that you are using in your project.*
Moving forward, we will host TOS changes on Github to give developers full transparency about what changes are happening, and when. The link is https://github.com/Unity-Technologies/TermsOfService.