Of course Ohio State is a better program historically. I was born in 1976 and started watching basketball regularly in the mid-80s. Ohio State was probably somewhat better than Xavier in that era (pre-Matta), too, but it wasn't much of a gulf. Certainly not one to be "protected" by not playing each other.
Not that there was even a perceived rivalry/bad feelings on either side before Matta went from X to OSU.