I've made this point many times before, and probably will make it many more times: higher-than-average intelligence isn't required for intellectualism. All that is required is an intense interest in intellectual subjects.
For example, it is almost sort of a given for INTPs to be intellectuals of a sort (the thinker, the philosopher...) But where in the type description does it say that they are all amazingly smart? Maybe in some of the descriptions, but the good ones are supposed to be purely about personality, not about ability. It is an unfair thing to have a very intellectual personality but to have to add a "pseudo" to that because of weak reasoning abilities, flawed logic, etc.