Well, let's be fair - we do know why people post this stuff - and it's because they're big fat attention seekers. Still, we don't get it.
8. Why Men's And Women's Shirt Buttons Are Still On Different Sides
Historically (though there's no evidence) this is because men have always tended to dress themselves, and are mainly right-handed. Women, on the other hand, would be dressed by maids (those that could afford fancy clothes, anyway) so the buttons are on the right side for the generally right-handed maids. Still, that doesn't explain why it's still done today. WHY.