30/30 rule and the opposing obsession with youth

So J tells me about the "30/30 rule" that some women have - has even ever heard of this? Apparently it means that these women will only date men over 30 years old and who make more than $30K a year. This was new to me and obviously it was never anything that I followed (I started dating J in his early twenties) and I find it interesting that some women might find these things to be two such superficial things to be characteristics that they sweepingly look for in men.

Even more interesting is that older men are considered so attractive, yet our culture is obsessed with youth. Young men and women - often painfully thin and setting a poor example of health for their peers - are the models chosen to sell everything from anti-perspirant to cars. If youth is so important, why would women choose mates who are significantly older?

Does this merely point out that there are things stronger than our culture affecting human behavior? Perhaps there is something in our genetic code telling us what to look for in a mate - security, health, stability? Perhaps we associate health with youth and security/stability with age. Perhaps our civilization has come far enough that health is slightly less of an issue because medical technology has advanced far enough that most ailments can be cured. Alternatively, are we in the good 'ol western civilization just fatally materialistic and someone who's been in the work force longer is able to provide us a more comfortable lifestyle?

Just something to think about.