CathInfo.com

Well, you'd be surprised how little time theologians actually spent on BoD.  Very few even mention it, and those who do typically mention it in passing, simply repeating the notion that it exists.  Things get perpetuated through repetition unless someone takes the time to "dig into" an issue and look at the source material.  Very few theologians cared that much about this question to do original research, simply taking this conclusion for granted due to lack of time or interest to look into it.  So, no, they weren't "dumb".  They just didn't care that much about it by and large and didn't spent a lot of their time on it.  Father Cekada did a survey of all the theologians' opinions on BoD and he could only find about 20 (if I recall) in total, and the vast majority of it simply mentioned it in passing in a single sentence.

In fact, from the about the 5th century, when St. Fulgentius explicitly rejected BoD, until St. Bernard, there isn't a single mention of it anywhere in extant Catholic writing.  It resurfaced with the proto-scholastics, Abelard and Hugh of St. Victor, who were debating separate sides of the issue.  Peter Lombard then wrote St. Bernard, asking for his opinion on the subject, and the latter TENTATIVELY went pro-BoD with the argument, "I'd rather be wrong with Augustine" than right on his own (a posture of humility).  He was evidently not aware that St. Augustine had forcefully retracted the opinion.  Had he known, he would have had to decide whether to be right with early Augustine or right with later Augustine.  Peter Lombard than put that opinion into the Sentences, which became the first scholastic theological treatise.  From there St. Thomas picked it up, and from him it spread ... due to his authority.

May I ask for a source/reference?