If the feature can sometimes be useful (including this situation, which some other comments mentioned; but also for other things such as hiding actual secure data), then perhaps it should be made as a setting which can be changed in the setting menu (e.g. "Exclude secure data from screenshots"; it should also mention which apps use this feature), so prevent abuse. (This would also make it clear what the feature is, as well as being able to disable it.)

That such a setting does not exist suggests the feature's true purpose is not for the end user's own benefit!