I think it has resulted in a great deal of innovation; just in the last couple of decades, there's been the space shuttle - a rather inefficient, expensive system but one which has nevertheless taught us a great deal (and there have been >130 shuttle launches - despite two catastrophes, it's the mark of a successful system that shuttle launches have become commonplace); the Hubble Space telescope, which has operated for far longer than expected; The Earth Observing Missions; we've successfully sent two robots on Mars which have kept functioning for 5 years; we've gathered samples from comets (subject of another HN thread today)...for a list of missions: http://en.wikipedia.org/wiki/List_of_NASA_missions

For context, here's a brief history of NASA budgets: it's really quite good value in my opinion. http://en.wikipedia.org/wiki/NASA_Budget

Now, I don't think NASA is beyond criticism...but to say they haven't innovated or done a lot with the resources available is just BS. NASA is the most successful space agency in the world, by a very long way.