Peter Lombard was allegedly one of the most important theologians of the Middle Ages. As Wikipedia states, he was:
Bishop of Paris, and author of Four Books of Sentences, which became the standard textbook of theology, for which he earned the accolade Magister Sententiarum. [...]
From the 1220s until the 16th century, no work of Christian literature, except for the Bible itself, was commented upon more frequently. All the major medieval thinkers, from Albert the Great and Thomas Aquinas to William of Ockham and Gabriel Biel, were influenced by it. Even the young Martin Luther still wrote glosses on the Sentences, and John Calvin quoted from it over 100 times in his Institutes.
Later on the article mention just one doctrines with seem to be relatively controversial, but yet far from being declared heretic. It is know that even St. Augustine wrote things which are not in line with current official teaching or dogmas.
The Catholic Encyclopedia states about him:
On the whole and in spite of his connection with Abelard, he is orthodox; a proposition of his on "Christological nihilism" was condemned by Alexander III; other theses were abandoned in the century that followed; St. Bonaventure mentions eight of them and the University of Paris later added others. But the success of the book was incontestable; down to the sixteenth century it was the textbook in the university courses, upon which each future doctor had to lecture during two years.
Later on, the article states:
[T]he success of Peter Lombard was not immediate. Attacked sometimes during his lifetime, as Maurice of Sully among others relates, after his death he was bitterly inveighed against, especially by Gautier of St. Victor and by Joachim of Flora. This opposition even went so far as to try to get his writings condemned. In 1215 at the Lateran Council these attempts were baffled, and the second canon began a profession of faith in these words: "Credimus cum Petro [Lombardo]".
So he or his writings (except one or two points, it seems) were never really condemned. And yet, he seem to have never got ground for reverence among other great theologians of the Middle Ages. Is this the case? How can we explain this?