It's not "mass hysteria" to observe that your business partner is willing to attempt to retroactively change the terms of your arrangement with them, and theref

It's not "mass hysteria" to observe that your business partner is willing to attempt to retroactively change the terms of your arrangement with them, and therefore decide they aren't trustworthy as a business partner. The actual monetary cost to developers is actually quite inconsequential compared to the lack of integrity Unity showed in trying to make this apply to games which were already released.