Yes, there was a time that Sportscar racing was governed by the FIA and they , of course, did want it to compete with F1, so they destroyed it (or tried).
Today it is under the ACO, which despite some "unusual" ideas are doing a reasonably good job of getting sportscar racing back on track (sometimes they shoot themselves in the foot such as the recent very biased pro- diesel rules that essentially chased away any manufacturer that had little or no interest in selling diesel cars).
Last years Le Mans had about 250,000 spectators , so things are slowly getting back on track. (no pun intended)
The ALMS is really booming (unfortunately the combination of the financial crisis and an upcoming rule change for 2011 have wekend the ranks for this year). Last year it was magnificent!
The LMS in Europe is growing at a much slower rate, but it is also less prone to the effects of the rule change and financial crisis as it is made up of a lot more "private"entries.