In Gen 2, male and female Pokémon have the appropriate mechanical roles; male Pokémon have higher attack and pass down their moves, while female Pokémon are valuable for breeding (just like real life). Later generations ruined this dynamic by giving females equal attack and letting them pass down egg moves too (also kinda like real life).
or way more likely it's because they were just trying to squeeze in new stuff that'd be forwards and backwards compatible between gens 1 and 2 so new characteristics for mons like gender, shininess, HP type, etc. were determined by existing data, and that became completely irrelevant once gen 3 came out and rewrote mons' data structures and didn't implement gender attack disparities because the new system would support having gender be determined by a separate part of a mon's personality value instead of just tying info like that to IVs, and trying to re-add that wouldn't be worth the effortand unlike hidden power which can be relevant in playthroughs, trying to tie gender to IVs would be completely irrelevant at best and an annoyance at worst and therefore not worth the effort to program inwhat you're implying is just a coincidence due to programming constraints and nothing more
