In the Commentaries of the New Testament the Fathers speak worthily of St. Joseph, still he was not much invoked (invocation itself, by the way, has grown immensely in the Church). It may be, as you say, that he was considered as being one with our Lady. More probably Providence kept him back that simple people might thoroughly take in the Incarnation, and not pay undue worship to St. Joseph. Gerson first roused the attention of the Church, and since his time God has in a way made it up to the holy Patriarch by the extraordinary devotion which has entered into the daily life of the whole Church, with so many blessings in the temporal and spiritual order.
To me it often occurs as one of the problems of our religion, how men have advanced so slowly in the comprehension of the Incarnation and its consequences. The faith of the Church has been constantly expanding, and there is every reason to believe that it will continue to expand to the end of time. The group of the Holy Family we see in a way completed in the minds of the faithful by the devotion to St. Joseph.
Link (here) to the portion of a letter by Bishop George Porter, S.J. from the book entitled, The letters of the late Father George Porter, S.J. Bishop of Bombay.