system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:Why did channels like TLC, The History Channel and Discovery Channel switch to airing only shitty scripted reality shows and stop airing anything of substance?
gpt
They try a show and when that show has lots of viewers they get more ad money. They then try to replicate the success with a similar show and that continues until there are not enough viewers to justify the production costs. 

Tldr: because people watch it.