It's unfortunate but perhaps inevitable that you get more attention when things go wrong than when things go right. So it was with me and my late father when I was growing up, and so it is with NASA, which is having a bad couple of days. The sabotage of an ISS-bound computer by subcontractor's employee and the embezzlement of $150,000 by a former NASA employee can't be seen as a reflection on NASA's "character" or even on its management - some people do crazy and irresponsible things, and no organization is immune to such incidents. It's lucky that the sabotage was discovered by the contractor and did not result in any serious problems (it was said that it would have been discovered in safety checks before launch even if the contractor had missed it, and it was not mission critical hardware).
The two reported drinking incidents are a different story and certainly reflect poorly on the the judgment of the individual astronauts involved and on any fellow astronauts or managers who allowed an impaired astronaut to operate or fly anything. This is obviously a safety issue and the incidents and individuals involved should be investigated and disciplined as appropriate based on the findings, and if such behavior is more than just a couple of isolated incidents, this should obviously be corrected.
But it's unfair to assume that it's widespread or that it's a "NASA problem" or to chalk it up to shoddy management or even to "macho test pilot attitudes" of the astronaut corps until more facts are available. NASA employs some 18,000 people in addition to many contractors who work indirectly for the space agency. It manages some 70 different space programs along with the countless other activities required of a government agency with widespread and wide ranging responsibilities. That's a lot of people and a lot of activity.
I'm not saying that NASA is perfect - what organization is? They employ people, and people sometimes make mistakes and bad decisions. But from everything I've ever heard and read, and from the NASA people I have interacted with over the years, I believe that the vast majority of NASA's employees are dedicated and professional, and they certainly accomplish a lot of amazing and important work. I think we should try to keep a little perspective on these stories, though I suppose that's a lot to expect in a time when the antics of Paris Hilton and Lindsay Lohan are staples of "news" coverage.