For one, there's the obvious reference/fulfillment (quoted in John 2:17):
Psalm 69:9 (NASB)
For zeal for Your house has consumed me, And the reproaches of those who reproach You have fallen on me.
My first thought is that Jesus, knowing their hearts (Mt 9:4, Mt 12:25/Lk 11:17), might have known that reasoning with them wouldn't have worked. (e.g. Lk 16:30-31 or perhaps even Pr 26:4)
Defending His Reputation is Helpful for God's People
There's a way in which God will defend his reputation, particularly among people who claim some knowledge or understanding of him, for the sake of those people, so that they realize that God does not approve of these actions. Numbers 25 has a good example of this. Phineas is praised, not because he killed a flagrant offender, but because he understood God on the matter. Brazen immorality among God's people isn't to be tolerated. God's chosen people are supposed to be a "light to the nations" (Is 42:6, Is 49:6, Is 60:3), and when they do things that openly damage those people's understanding of God, he doesn't always tolerate it for long.
With my own children, there are offenses for which punishment is swift and no warnings (need to be) given. They already understand how wrong it is, and even a moment of high emotions and weak spirit is no excuse for what they've done. Reasoning with them doesn't always do much good, since reasoning will only reveal to them why what they are doing is wrong. If they already know it's wrong, reasoning won't necessarily produce a change of heart necessary to repent.
These money changers in the temple were cheating the people. They were oppressing these people who had come to pay homage to the living God. It seems justifiable (to me) that Jesus would get angry enough to drive them out (shamefully, for them) because of what they had been doing. It seems likely (to me) that they had been doing this long enough to have had the opportunity to realize the enormity of their endeavor but didn't care because they wanted the money. Can you reason with greed?