But end users use the same mechanism to theme their apps as vendors and that one is being removed.
Now you know why the application developers are so loud and angry. We can’t have nice things because distributions shipped broken default configurations, and that’s messed up.
If you have a feature that is used by one customer out of thousands but it's causing problems at every update you push out. It might be better to remove the feature and fire the customer, than to keep supporting it no matter what.