My personal opinion is that highly learned theologians disagreed with the Bishops and other highly learned theologians who wrote the Vatican II documents.
It is also my personal opinion that change is hard, and religious change is even harder.
For one group to complain that the other group isn’t using the “right” words or language is akin to the question of how many angels can dance on the head of a pin.
Having read 6 of the 16 documents of Vatican II (still working on the rest), I can’t see any false doctrines, new pronouncements of dogma, or anything of the like. Rather, what I have read is the affirmation of Church’s teaching, an exposition of the proper relationship between the laity and the clergy, as well as stream-lining and harmonizing of rites, etc.
Can honest people disagree, of course. Should it create division in the Church, NO!
Jesus promised Peter the Gates of Hell would not prevail. We should trust in Him, follow the Scriptures, and be nourished by the Magisterium of the Church.
When reading equivocal language with a proper Catholic formation, one might come away with a Catholic interpretation. But why even use imprecise language when the proper tools for theological discourse are readily available?