It wasn't what they were doing, it was where they were doing it. There are some things that shouldn't happen in the house of God, and those that use God's name to promote their own pockets will be judged for it.
The moneychangers were doing an important function in the operation of the Temple and their presence was approaved, even required, by the priests who ran the Temple. They had yhe right to be there. If Jesus thought otherwise, he could have complained to the priests or arranged peaceful protests. We are taught it is a sin to attack others or disrupt their lawful occupation. This is what Jesus is said to have done.
They thought Jesus came to overthrow their physical Kingdom. Since Jesus was the king. The feared the crowd were following Jesus instead of them.
Mark calls Jesus a carpenter, although Matthew, perhaps in deference, was reluctant to call Jesus a village carpenter and referred to him as "the carpenter's son". The other gospels do not refer to Jesus either as a carpenter or even as a carpenter's son. If Mark is correct, and Jesus was a carpenter, then he would have made tables.
Jesus was born and raised a Jew. At the time the Jews were being oppressed by their Roman conquerors and people were hoping for a Messiah who would overthrow their enemies.
He had righteous anger. The Bible says he had never sinned in his lifetime. According to Jesus, hatred is a sin.
Jesus upturned the money lenders tables in the temple:)
He was considered by both of them as a rebel trying to overthrow the roman empire and the Jews with his teachings.
Jesus cleaned the temple only once. When he made a rope and chased the animals from the temple and overturned the money changer and their tables.
On Tuesday of Holy Week, Jesus cleansed the temple in Jerusalem, overturning tables and driving out those who were buying and selling.
In the synoptic gospels (Matthew, Mark and Luke), Jesus overturned the tables and drove the moneychangers from the Temple just before his arrest and trial - in fact this was the final trigger for his arrest. In John, Jesus overturned the tables and drove the moneychangers from the Temple right at the beginning of his three-year minnistry. In all cases, the cleansing of the Temple only occurred once.
I think JESUS was between 32 and 33 years old but i am not really very sure of the exact age as this event happened before the crucifixion of JESUS by one week.
The land of Israel was dominated by the Romans. Jewish people looked forward to a Messiah to lead the nation to greatness and to overthrow Roman domination.