Here's another view which would challenge your reading of that particular text:

http://blog.compassion.com/the-poor-will-not-always-be-with-you/

There is also the argument that Jesus is referencing Deuteronomy 15.11 "For there will never cease to be poor in your land." That text goes on to say, "Therefore I command you, you shall open wide your hand to your brother, to the needy and the poor in your land."