Like all political executives, he doesn't encourge citizens to help with law enforcement. There are various reasons for it.
Myself, I think that the Minutemen are a good thing.
After 911 Bush only tried to get the postal workers, the cable guy, and meter readers to keep a watchful eye in the homes they go into (until the companies refused to allow their employers to do it)
AND
He was in Portland, Maine telling the lobstermen that we need to be "VIGILANT" and suggesting that they keep an eye on the port and report anything that appears strange.
Come to think of it... "AMERICANS NEED TO BE MORE VIGILANT" was one of Bush's favorite statements a couple of years ago.