Why have TV networks such as Discovery, History, Animal Planet, etc. seem to have "dumbed down" their shows in recent years?

I feel like I'm in the movie "Idiocracy".
When the History Channel first aired, its programming consisted of classic documentaries that actually taught viewers about history [1]. However, over time, the channel shifted to reality television show programming, which includes popular programs like Pawn Stars and American Pickers [1, 2]. While some people may consider this a decline in quality, the network management knows that as long as the shows are popular and bring in traffic and revenue, they will continue to air them [1].
There are two main reasons why TV networks have shifted toward reality TV. First, reality TV is dominant because of the high revenue return potential and simple production value [2]. While the costs of paying some reality stars has increased exponentially, the costs of producing reality TV is still a lot less than creating most scripted programs [2]. Reality TV helps networks and cable channels can capitalize on ad revenues over longer time spans [2]. At the same time, salaries for popular reality stars have shot up exponentially [2]. For example, actress and reality TV star Denise Richards reportedly made $1 million per season on Bravo TV's The Real Housewives of Beverly Hills [2]. Second, reality TV is more digestible and less expensive to produce than scripted shows [2]. Reality TV requires fewer writers, which helps lower the cost, and placements are easier to digest and serve as an important source of revenue [2]. Overall, TV networks have shifted toward reality TV because it's more profitable and draws in audiences more effectively than educational programming [1, 2]. 