Spousal retirement benefits are part of the original Social Security legislation that was effective in 1936 following the Great Depression and passed during the FDR era. Originally spouse's benefits were only available to women based on the assumption that were the primary bread winners and had higher lifetime earnings than women (which was a valid assumption in 1936). Over the years, society has changed but the legislation still exists.

To this day, many women who have been stay at home wives (AK housewife) can get retirement benefits on their husbands when they reach age 62 IF the benefit on the husband is more than twice what they get on their own. A change in legislation sometime in the 1960's or so added husband's benefits. Now the rules are the same for both genders.

Nothing new.