Why do so many of you bade your self esteem off the amount of sex you have with your spouse?

Why is it that the first thought that comes to mind for a lot of women is that their spouse is no longer attracted to them and then your self esteem is shot? I'm really curious. Why doesn't anyone take stress or medical issues into consideration before jumping to the conclusion that he doesn't love you anymore? I don't know, it just seems like a lot of women base their self worth on how much sex they're getting. I had a hard time wording this. Hopefully it makes some sort of sense.