Quite frankly, that's bullshit. Romney/Ryan advocate a rollback of my rights and continued (or furthered) discrimination against me. That's only one small social issue that they differ on and they differ on policies that involve much more substantive issues.
Maybe you're privileged or fortunate enough to not be affected by tax rates, women's rights legislation, gay rights issues, and more, but many of us aren't. Those issues matter and that's why some support Romney and some support Obama.