Caths will object to that since Joseph had nothing to do with proving material for the incarnation (and according to Caths, the man never even consummated the marriage, contra Gn. 2:24; Mt. 19:4,5) but neither did Mary provide any material for Christ being God, while the logic that "Christ is God made flesh, Mary is His Mother = Mary is the Mother of God," also means, "Christ is God made flesh, the Jews (via Romans) murdered Christ = the Jews killed God/God died."
Aside from the fact that we all did so, such language, while technically allowable in a qualified context, is contrary to the Holy Spirit's language, which even qualifies that while Christ came out of Israel, qualifies that by saying, "
of whom as concerning the flesh Christ came, who is over all, God blessed for ever. Amen." (Romans 9:5)
And "Mother of God" is nowhere chosen by the Spirit, and which, as with stating that God died, most naturally sends a message contrary to Scripture, in the first case it infers that Mary is ontologically the mother of God, and in the second that God can die.
Thus need to give reverence to the language the Spirit chooses and the appellation He gives to man, but in contrasts, Catholics even tend to shun Theotokos - God-bearer in favor of "Mother of God," capitalized "Mother" no less, and which is part of the idolatrous adoration of the fictitious Mary of Catholicism, who is [FONT=Arial, sans-serif]
exalted (officially or with implicit sanction) as
• an almost almighty demigoddess to whom "Jesus owes His Precious Blood" to,
• whose [Mary] merits we are saved by,
• who "had to suffer, as He did, all the consequences of sin,"
• and was bodily assumed into Heaven, which is a fact (unsubstantiated in Scripture or even early Tradition) because the Roman church says it is, and "was elevated to a certain affinity with the Heavenly Father,"
• and whose power now "is all but unlimited,"
• for indeed she "seems to have the same power as God,"
• [FONT=Arial, sans-serif]"surpassing in power all the angels and saints in Heaven," [/FONT]
• [FONT=Arial, sans-serif]so that "the Holy Spirit acts only by the Most Blessed Virgin, his Spouse." [/FONT]
• and that “sometimes salvation is quicker if we remember Mary's name then if we invoked the name of the Lord Jesus,"
• for indeed saints have "but one advocate," and that is Mary, who "alone art truly loving and solicitous for our salvation,"
• Moreover, "there is no grace which Mary cannot dispose of as her own, which is not given to her for this purpose," [/FONT]
• and who has "authority over the angels and the blessed in heaven,"
• including "assigning to saints the thrones made vacant by the apostate angels,"
• whom the good angels "unceasingly call out to," greeting her "countless times each day with 'Hail, Mary,' while prostrating themselves before her, begging her as a favour to honour them with one of her requests,"
• and who (obviously) cannot "be honored to excess,"
• and who is (obviously) the glory of Catholic people, whose "honor and dignity surpass the whole of creation."
Sources and more.