The concept of the storylines was just fine with LCS, why they changed it and started humanizing the characters more and getting down right silly is where they totally lost me. IV and V both couldn't make their minds up if they wanted to be a parody or a serious story at the same time.
You are slightly on the right track. They are serious stories of serious people in a satirical world. Personally, I like that direction and its usage in Grand Theft Auto V's storyline.