Don't mean to defend the execs that made this decision too much, but I think saying "they're all just idiots" is probably not what really happened.
Basically, execs (especially public company execs) have the responsibility for growing revenue and earnings. Ideally they do that by just making better products, but some times you do need to "thread the needle" by charging more for your products while not pissing off customers too much.
I'm sure the devs and customer support folks were screaming bloody murder, but they are also not responsible for satisfying public markets, so it's easier to say those things without having to worry about revenue growth.
So point being, I'm sure execs thought there would be some blowback, but they probably felt it would be "manageable", and like others have said, they overestimated the irreplaceability of Unity. So its important at the exec level to have someone who can whisper in your ear, someone who does understand the requirement for growing revenue, that can honestly say "you've managed to convince yourself of this bullshit."