Also St Jerome held many opinions about which books ought to be in the canon, because he also had the Catholic liberty to do so, because in those days it was quite unsettled. Yet, the councils of the Church codified a canon that we are bound to as believers.
The problem with Protestantism is that the famous Lutheran mantra, the “sola’s” of the faith, are refuted by their very description: sola scriptura, sola fide, sola gratia.
One cannot have three distinct sola. “Alone” denotes, as does the original Latin, ‘sola’, an isolationist perception. If it is faith alone, then only faith alone can save: this bars grace and scripture. Or, only scripture alone, and that would bar grace and faith. Or, only grace alone. You know what I mean. One cannot, simultaneously, have a mantra of three (or five) different “sola.”
But on the other hand, it never was Luther’s intention to begin a new denomination based on his writings and theology. Yet heresy is heresy. To reject the traditions of the Church that were codified through Councils past would be to say that the Holy Spirit had abandoned the Church, which never will, nor ever has, happened.