Historically, the people in wrestling who were the biggest draws and made the most money also were the most charismatic. Like Loss said, it's not like it's an either or deal where you can only be one or the other, but those who have charisma and lack the in ring ability tend to have more success than those that have the ability and lack charisma.
I think a part of it is cases like Hulk Hogan and the Rock, who pretty much lapped the competition in their eras in terms of charisma it created a sense of "well no one can compare to *that* so why bother". One thing I always seem to notice when watching old territory stuff on either the Network or Youtube is how much more charisma I see in mid or lower card guys. Part of it might be it stands out more because it's not something common in today's overscripted WWE style, but it shows how important making a connection (or at least trying to) was in the days where your income was based on the size of the house. Everyone had a vested interest in getting an ass in every seat.