I was privileged to grow up in a MO right household and veered towards Yewshiva in my teenage years. When Shidduchim came up, I was pushed by my family to date more “MO” girls who, while being of very fine character, didn’t share the same goals as I did. It didn’t require intense introspection to uncover that the true difference lied in a vastly different perspective.
It would almost be akin to having an ardently vocal Trump supporter attempt to date an ANTIFA member. I don’t mean in the level of extremity of these types of people, rather in their vastly different views and the consistent nature in which those views would arise and cause conflict with one another in daily life.