Some things to consider in response to some of the posts here:
While the existence of the type was known about by opposition forces and spotters, what wasn't known by them was the quantity of airframes, weapons capabilities, ability to deploy to regional conflicts or the range of the airframe. Also, with this type it was a long time before enemy radar operators truly knew what effect stealth had on their air defences. So knowing about the airframe was one thing, knowing whether or not to be scared of it was something only the Americans knew for a good 10 years.
In the last 5 years the F-117 rapidly lost out to the F-22 in both political and financial priorities and technical capability. The F-22 had a level of stealth greater than then F-117, apparently, and can carry a much wider range and quantity of weapons into denied territory, along with significant ESM/data capabilities that the F-117 would never have. Trials were made of F-117s painted grey in an attempt to give them a daylight role but even by this time it was obvious the F-22 was going to win. Also, not having even a supporting role in the post-2005 era of pain and re-grouping experienced by the US in the two Middle East conflicts meant they were always going to be struggling for investment. Even the E-6B TACAMO aircraft found a role in Iraq….
Something else to consider is that the F-117 was built in an era when 'what happened at Groom Lake stayed at Groom Lake', hence apparently many very dangerous chemicals were used in its RAM materials which may not have been quite so legal when the aircraft had to be treated like just any other in the fleet by the 21st century USAF, see the Area 51 worker lawsuits for further details. I suspect this is the reason that most of the airframes were stored at TTR before being destroyed, not kept at the Boneyard or museums like most other retired fleets.
There were 2 (certainly less than 5 officially) F-117s kept in flyable storage post-retirement and at least one of these has been seen flying recently over Nevada. Flying it over a military test range where you can avoid schools, hospitals and anyone with breathing difficulties should one crash is very different to re-activating them as a globally deployable weapons system.