The No-Nookie Movement: Why Wait?

There's been a fast-spreading and unwritten rule that has taken hold in dating circles.
It's not by any means new, but it's so well embedded now that no one even thinks about why it's in place these days.
The No-Nookie Movement.
It's when women and men effectively put a timer on sex. They say "Well I have a 3 month rule" or "two-week" rule that they follow before having sex with a person.
Now, who came up with this is not as important as what its actual purpose is. The logic seems to be that you don't really know a person right off so you'll just take a few weeks, a few months, always a "specified" period to get to know the person.
Of course, in this world it's mandatory that you know who you're sleeping with since your genitals will fall off if you don't.
But my only point is that the No-Nookie Movement, with a specified date, kind of defeats the purpose.
Example: If I KNOW that a safe with $1 million automatically unlocks in six days, and I'm on Day 2, then I'm going to chill until DAY 5.7!
If I KNOW without a doubt that I can access a cookie jar at midnight and only at midnight -- that's the specified time --- then all I have to do is put myself on cruise control until 11:55ish, and I'm GOOD.
The NNM would work sooo much better if there was no specified time. Then it would be honest, genuine (kind o' like the Second Coming, you don't know when, but you know you'd better be right?) and you couldn't cheat.
See, if you tell somebody you really like "I have a waiting period. There's no timeframe attached to it, it's basically up to me and my comfortability" then ya gotta respect that, right?
Face it, most of these relationships end with "I thought I knew him..." anyway, right? But if you basically 'assign' a motive (wait for nookie to become available at "..." time) then you can't be mad when he operates on that.
But if you say, "These brownies will be ready at 3 p.m. ..." Get it?