I don’t think it is so important who won those tournaments in the past. For example in 2004 Massu was the Olympic champion, and this fact is often used by those who try to dismiss the prestige of Olympic tennis. But Federer was is the draw and desperately wanted to win Gold. It’s not Massu’s fault or the fault of the Olympics in general that Berdych stopped Federer.I don't understand the hype about the Olympics. It wasn't that big of a deal before 2008, despite beginning in 1988. It is important because you play for your country, but a tournament that is played once every 4 years should have no bearing on someone's legacy. And it certainly shouldn't be ranked above a tournament like the WTF that has a rich history since the 1970's. All the ATG except Nadal and Wilander have won the WTF. No way it should rank below Olympics and just above the smallest tournaments given the quality of the winners at this event.
We can go even further back: In 1992 Marc Rosset won, but Courier, Sampras, Becker, Edberg, Muster, Bruguera, Ivanisevic etc. were in the draw.
I give you that 1988 was really a bad start though (only Edberg and Mecir were top players), but that was a singular occurrence.
Yes, there were also some withdraws in later years, but we shouldn’t overrate for example when some “patriotic” American players rather played something like Washington instead of the Olympics shortly before the US Open.
To make it short: It is not important who won in the past, but who tried. And even more important is who tries NOW. Judging by the behaviour of the big 4 (all of them!), the Olympic tournament is just as important as a Slam, and therefore just as difficult and prestigous to win. Definitely it is above the WTF or Masters (nobody of them would ever cry for one of those tournaments).