You are missing the point - by indicating ALL the emergency exits, crew encourage passengers to be aware of exits additional to those in front of them/beside them. These could be blocked in an emergency.

The pantomime with emergency card and physical gestures is a serious business, focussing attention on safety procedures, indicating to the hard of hearing where exits are and where they can look for further information.

It's true that some cabin crew have become a tad jaded in their presentation, but the best try hard to gain and maintain attention. Inattention to the briefing by frequent flyers probably contributes to the jading of cabin crew.