Not sure if it is just the BBC. When reality shows first came on air, and with paid SMS voting, no one expected it be a major money spinner for broadcasters. The layperson replacing professional actors (especially if they are vulnerable and flawed to some extent) and viewers having fun at their expense first became a phenomenon and now a prime time mainstay.
Slowly but surely quality gave way to crass and exploitative content and sadly viewers enjoyed watching people fail on air. Joey Essex is an iconic example. The print media has now used what was on air to drive their content.
It may explain why more folks are begining to focus on specific genres such as Sport, Documentary, Movies etc and paying for channels rather than wait for what prime time offers.