Is this what Jesus really meant? Let's look at the text in context:
"Meanwhile, Jesus was in Bethany at the home of Simon, a man who had leprosy. During supper, a woman came in with a beautiful jar of expensive perfume and poured it over his head. The disciples were indignant when they saw this. 'What a waste of money,' they said. 'She could have sold it for a fortune and given the money to the poor.'
But Jesus replied, 'Why berate her for doing such a good thing to me? You will always have the poor among you, but I will not be here with you much longer. She has poured this perfume on me to prepare my body for burial. I assure you, wherever the Good News is preached throughout the world, this woman's deed will be talked about in her memory.'"--Matthew 26:11
So Jesus and His followers are dining at Simon the ex-leper's house, when out of the blue this strange woman comes up and starts pouring top-quality perfume over Jesus' head. The disciples, once again, don't understand what's going on, so they say she could have sold the perfume and given that money to the poor. And that's when Jesus says, "You will always have the poor among you, but I will not be here with you much longer."
Jesus isn't rebuking the disciples for wanting to help the poor, but because they didn't understand that Jesus was about to die.
As the book of Ecclesiastes says, there is a time and place for everything. And I think this passages in Matthew 26 is trying to say there is a time to go out and serve the poor, and then there's a time to spend it with Jesus--especially at that particular moment when He was about to be arrested.
It's interesting to note that this isn't the first place the Bible says we will always have poor people. According to Deuteronomy 15:11, "There will always be poor people in the land. Therefore I command you to be openhanded toward your brothers and toward the poor and needy in your land." So perhaps Jesus was referring to this verse when he told the disciples, "You will always have the poor among you."
So there you have it: Jesus isn't saying, "Don't bother fighting for poverty." He's saying, "There's a time for charity and social justice, but right now it's not that time." Got it?