But here is the thing, you are discussing of whether or not they could do other video game properties, when you should be asking if they should.
You are equating the signs of a completely different audience from a completely different region, not in the western audience, and more eastern, as mentioned with Final Fantasy and Monster Hunter. Can they be large video game properties? Yes, they are, but it doesn't always equate to having a large turnabout domestically for a theme park experience.
It's a niche market, with only a few outliers being able to stand out on its own, and for Universal, Nintendo has seemed the most cooperative and working in a sturdy relationship, with the Illumination deal and the theme park rights. It speaks more volumes to what it implies, and that both NBCUniversal/Comcast and Nintendo want to have the same goals reached in the best way possible.
Mario, is going to pull people in far more than two rated M titles, a slowly growing Capcom brand, and a somewhat dodgy Square Enix property, and it would be nonsensical to think that those other IP's can beat Nintendo in public awareness.