These exit polls are clearly scientifically invalid, and trying such artificial modifications as changing the age of the interviewer is akin to changing from chickens to ducks when you read the entrails.
Polling during the campaign season, even given its scientific invalidity, can at least used by campaigns to do such things as allocating campaign resources since they don't have any other tools except experience (a speedometer that's off by 5 miles per hour is still more useful than no speedometer at all), and experience generally does not catch new trends.
But an exit poll isn't even useful for that; the campaigns have no need for such polling data.
What else do the talking heads have to talk about then and how else can they continue to cheer on their favorites?