26 When Jesus therefore saw his mother, and the disciple standing by, whom he loved, he saith unto his mother, Woman, behold thy son!
27 Then saith he to the disciple, Behold thy mother! And from that hour that disciple took her unto his own home. - KJV John 19:26,27
We are not seeing Joseph near cross? Why did Jesus hand over his mother to his disciple? Where are his brothers and his father? Is there a history attached to it?
SO, according to Tradition, Joseph had long since passed when Jesus even began his ministry, making him ineligible. The next question is "Why didn't Jesus entrust his mother to one of his step-brothers then?"
Has anyone ever argued that it was "because God wanted him to go on to write Revelation and needed a model of the Heavenly Jerusalem"?
I don't know, beyond that, Catholics believe that Jesus "Gave us His Mother" at that point and we all should take her into our home.
The words of Jesus to the beloved disciple: "Behold your mother" (Jn 19:27), assume a particular depth in the life of consecrated persons. They are invited to consider Mary as their mother and to love her as Christ loved her. More especially, they are called to take her into their home, as John "took her into his home" (literally "among his possessions"--Jn 19:27). Above all, they must make room for her in their hearts and in their life. They must seek an ever greater development of their relationship with Mary, model and Mother of the Church, model and Mother of communities, model and Mother of all whom Christ calls to follow him. (Pope John Paul II, Mar 29 1995 Audience)
Whether this is scripture interpreting scripture or useless conjecture is up to you to decide.
According to Orthodox/Catholic tradition (mariology), in this moment Mary is given to the beloved disciple (john), and all the faithful so that she would be in a position to pray for her children (the church) as a physical mother does. As the mother of Jesus (Mother of God), Jesus honers Mary in a unique way. (Honor your father and mother). Catholics see The Wedding Feast at Cana as evidence that Jesus takes his Mother's petitions very seriously. Seriously enough, in fact, that his first miracle (recorded), and the beginning of his public ministry would be at the petition of his mother.
John 2:3-5 New Living Translation (NLT)
3 The wine supply ran out during the festivities, so Jesus’ mother told him, “They have no more wine.”
4 “Dear woman, that’s not our problem,” Jesus replied. “My time has not yet come.”
5 But his mother told the servants, “Do whatever he tells you.”
The Lord intended that He would leave His grieving mother in the best of care. It is not certain that at that time His brothers believed in Him.
John 7:3 So his brothers said to him, “Leave here and go to Judea, that your disciples also may see the works you are doing. 4 For no one works in secret if he seeks to be known openly. If you do these things, show yourself to the world.” 5 For not even his brothers believed in him.
If we remember that the whole Gospel of John takes a very short "snapshot" of the life of Jesus (~22 days) then we can see why The Lord left the care of His mother to John. John was a believer, His brothers were not at this time, and since His mother was a believer, it was better that she be taken care of by another believer.
I deduce from this that it is more important to be in fellowship with God's people than all the world, even our own siblings/family.
