Top Stairway

"There would be one long stairway just going up"
- Fiddler on the Roof soundtrack, "If I Were A Rich Man"

Our local station for "Classic Rock" (translated as "the music that, in saner times, used to just be called 'Rock' without need of further modifier") had their annual Thanksgiving Weekend "Top 1043 songs of all time" contest. Once again this year, as in 2006 and 2005 and every other year in living memory, the #1 song was - drum solo please - Led Zep's Stairway to Heaven.

And once again this year, I admit to being genuinely at a loss to understand this. Why does this song - one that was never even released as a single in the US - have an unbreakable hold on the top spot?

Don't get me wrong. I like StH, I truly do. It's a great song. But I can easily list 25 rock songs I personally prefer to StH, and probably at least 100 others that I like as much. I've never even met anyone whose favorite song is StH. So why does it win every single year, in every top 10xx countdown, on every (classic) rock station I've ever listened to?

Is it some kind of musical Harmonic Convergence? Does StH somehow appeal to fans of every possible sub-genre of Rock, such that even if it isn't the favorite of any one group of fans, it gets enough votes from every sector to always garner a majority?

Is it a self-fulfilling prophecy, via some kind of subconscious ballot stuffing by the collective rock-listening public?

Do the stations just automatically place StH in the top spot without regard to the actual voting? Is it the Third-World Dictator of rock music?

Is it a time paradox: Does StH always win because it always did win?

Or is it simply the title? Is the "Heaven" that the "Stairway" leads to nothing more or less than a permanent #1 slot in countdowns?

In all seriousness - does anyone have a plausible theory?