God is so upset with hypocrites because He dislikes the outward show of piety that hypocrites bear.  Hypocrites fast and pray in public - they follow rituals to the core and fail to practice the virtues of kindness, generosity, forgiveness and love.   They hold themselves higher than their neighbours - imagining themselves be God's chosen ones - but failing to carry out the basic commandments of God - to love your neighbour as you love yourself.  God is upset with Hypocrites because they are busy pointing their fingers at others and their failings, but forget that three fingers point back at themselves.  Hypocracy is wrong - because God created us all with our own faults and failings.  He knows our every weakness and it is very wrong to try and show man that 'I am better than thou...'   It is wrong to put another man down for the faults he commits - it only shows that we are worse than them.