Actually it's a lot more applicable to more mature men in long term marriages.
Young guys and guys in new relationships are often naturally doing a lot of the things that make them more sexually appealing to women by default.
It's the guys that have been married/LTR for 10-15+ years that have let themselves go and have gotten into the "yes Dear" routine of becoming betatized and complacent in long term marriage that need to get off the couch and bump up their sexy.