There's big variation between airlines, though, so I think that's not the entire explanation. In many cases I think that there is nobody involved with the decis

There's big variation between airlines, though, so I think that's not the entire explanation. In many cases I think that there is nobody involved with the decision of which announcements to include who really has the job of caring about the overall passenger experience. In some airlines in Asia you get every announcement in three languages, and your IFE is interrupted by all of them, regardless of whether you understand just one. Even worse, they put short pauses between them, teasing you with a couple seconds of your movie before interrupting it again. A basic level of care would be to interrupt the IFE only for the language you had chosen for the IFE when you first sat down.