

They did think it through.
The money they make from advertising is the same whether you show up on time or not. I’m pretty sure reserved seating nets them more concession stand income as people know they have ‘extra’ time to buy something and still get the seat they wanted.
The really frustrating thing back when the ads were first being shoved in was not having a consistent amount of ad time, so guessing the real start time was a pain.
Because it keeps them rent payment from bouncing.