It's not inconsistent to claim that--it's rationally sound on paper; that isn't the problem. It's just that in the real world, human compassion compels me toward the view that making sure people can feed their families is more important than keeping your nominal income tax rate at the lowest possible level. I don't like welfare leeches any more than you do, but I think it's pretty callous to insist that no social support net should exist at all.
We don't even really disagree in principle; it's just a matter of degree. We both agree that the government should be able to force some taxation from the people for whatever things it needs to accomplish; you just draw the arbitrary line at a different place than I do. Many Libertarians seem to have the view that anyone who isn't as successful as they are simply isn't working hard enough, or is lazy, etc. Neil Boortz wonders, "Why doesn't everyone just start a law firm and make millions of dollars like I did?" But lots of people simply don't have the talent or intelligence to do that, and that doesn't mean that they aren't hard workers or that they should be denied basic necessities (this includes education) for their families. I believe capitalism is inherently superior to socialism, but I don't buy into the social Darwinist view that we should just let people die out if they're unable to support themselves. The balance, to me, is somewhere a little bit right of center...just not ALL the way to the right.
If you don't want government to do most of what it does, do the same thing anyone else who wants to enact political change does: vote your conscience and rally others to do the same. If you believe the executive or legislative branches are doing unconstitutional things, take it to the judicial branch and sue them.
That's great, but economic wealth is not always the most pressing issue at hand. It's an important value, but it's not the only value worth taking into consideration--Libertarian government would theoretically work if we just ignored the concept of human compassion entirely, but I think that's pretty impractical, personally. We have to be able to stop the social support net in places where people are abusing it, but that doesn't make it a fundamentally bad idea.