Why are older contestants never allowed on this programme? Is it because the producers know older people's knowledge is usually superior and the prize money won would be considerably more.!!!
As you say older people are usually more knowledgeable and they don't want anyone to clever on their quiz shows. A friend was interviewed via phone for Who Wants To Be A Millionaire and was asked how many popes there has been he give the correct number as he is a clever quizzer and he never heard back from them probably thought he was too smart for the show. Some of the questions recently on Million Pound Drop have been very crude and Davina in my opinion is very irritating!
As Grasscaro pointed out, it seems that being photogenic is more important than intelligence. The Vault (Ch 4 too) also seemed to have an under-30 age preference. Isn't that ageist?