Even those who are not actually in the middle class like to identify with the middle class. Sometimes you get qualifiers such as I am "upper-middle class" but it is all in relation to middle class. We demonize the highest 1% (and even more the .01%) of wealth holders and talk about how the lowest 1% are freeloading the system. We are frustrated when the economy does nothing for the middle class and if play a drinking game during a presidential debate only taking a sip when you heard any candidate say "middle class" then you would be passed out by the end of the first question.
Jesus was not middle class, and yet we want to make him fit there. We pacify the hard messages of Jesus and down play his anti-empire and political positions. We give him good looks in movies and we ensure he looks well fed in art. He comes from a family that gave the sacrifice of the poor (pigeons) but we recreate the upper room feast like that of a Norman Rockwell painting. We are quick to "understand" his teachings and speak of them like he is directing them toward us in the middle class rather than to those on the margins.
In fact Jesus was not the only spiritual leader that was from the margins. I don't know every story of every religious leader, but I am willing to bet that most religious leaders came from the margins and not the middle class of their time.
Christians give thanks to God for the incarnation of God in the life of Jesus. Perhaps it is worth further consideration that yes God was not born to a rich family, but also that God was not born to a middle class family.
Jesus is not middle class spirituality.