Well, I wanted to say the same stuff as @Sinan said.My friend , it affects people in long term . Showing cheating as a normal issue in every movie and serial for long time has no purpose but what I said .
That's not my logic .
Anyway, you are looking at it upside down. These channels are living on the amount of audience they have. remember they don't have any oil money. hence, they need to show what their audience want. when such stuff are extremely popular in Iran, they would obviously focus on showing them.