Prenups aren't for the happiest time of your life. They are for the possible, upcoming worst time of your life. They are like health insurance policies. No one wants to buy insurance or to think bad things will happen when they are sound, healthy & happy. Likewise, most people don't see the ugly, vile, evil side of a person during the happy times. That side usually comes out when the happy times are over.
As someone who works with abused women, they often don't see the punch until after they've been hit.

It's naive to believe the "happy person" is all there is. Any psychologist, profiler, police officer, security expert, or divorce lawyer will tell you that.
As for these kinds of prenups, I am all for them. If someone's been in a marriage for 7 years, and invested themselves, their time and energy into it for 7 years, they should definitely get more than if they were in it for only 3 years.
I once read that Catherine Zeta Jones has a "bad boy clause" with Michael Douglas. He was known to have sexual proclivities that helped end his first marriage. That he had a real bad boy streak during his
Basic Instinct and
Fatal Attraction days that weren't all make believe. Douglas helped popularize the term, "sexual addiction."

(Now, it's probably be called being Tiger Woods.

) Zeta Jones knew full well about his reputation. She actually helped tone down his reputation by being with him.
Allegedly, Zeta Jones gets another few million if they divorce, on top of what was agreed upon, if he's been proven to have been cheating. And for every 3 years they've been married, the payout goes up percentage-wise according to how long they've been married.