Richard,
true for the English, but didn't the French celebrate theirs? especially Guynemer?
that said, i don't see an inordinate fuss over German aces in general, so much as Richtofen and Voss. not only two of the most famous aces of any nation, but two of the more famous air combats (although i think Richtofen's last has more to do with it being Richtofen). i get the impression that Richtofen was the most famous flyer of the war to all sides. part of this was British policy vs German PR, but he *was* the ace of aces.
Voss, on the other hand... Voss' last flight may be the most dramatic combat between aces. i suspect had Voss got the better of McCudden and/or Rhys Davids and escaped, the day would be just as famous and the anniversary of McCudden's end would be more of a day of note than his actual end due to mechanical failure.
McCudden has a lot to do with the fame of Voss' last combat, too. McCudden is so very matter of fact and down to earth in most of his writing, that you the reader trust what he says about Voss. from anyone else it might look like hype.
bottom line is Voss was one of the most special of the special. he flew astonishingly well and impossibly bravely against the best of the best. so well, that had he more luck with where the bullets landed on those SE5as, the outcome could have been very different.
to my eye this one event embodies everything that's so fascinating and terrifying about WWI air combat. they were doing these things in kites i'd be terrified to go up in. blows my mind over, and over, and over...