Comment 26 for bug 274461

It is stupid to have the apps set opacity, that is Compiz' job. If you put the settings in the apps the user has to control them per-app. If you let the compositing manager handle opacity then all the settings are in one place.

It's not a feature, it's an intentional bug, and it's done the WRONG way. I would go so far as to say it's done the anti-Unix way, which is to have small tools that work well and don't have too many features. This is definitely a feature that doesn't belong in the tool since the typical desktop already has a mechanism for managing this.

BUG.