No one can really explain it. It's like Hendrix or Clapton. Both are limited to pentatonic/major scale riffs, and are consistently rated "greater than" Zappa or Clarence White or Carlton or Baxter.
Jimmy Page was great, and so was Townsend. Neither were most excellent as technical aspect.
Really think about it. Would any of the top Greats make a wage as a session guitarist? No. It's the band they were with, the times, the image.
It's the definition of "Greatest" that needs to be addressed. It's intentionally vague.
Not fastest, not melodic, Not anything other than Great.
The Flintstones was great. Hitler was great. I made a great dump this morning.
Second, consider the source.
Rolling stone stopped being relevant over 30 years ago.
My guess is it's a readers poll or, even worse, a poll of RS staff and content providers.
The most glaring evidence of the list's irrelevance is it's rating of Neil Young above Willie Nelson.
Willie Nelson is a very good guitarist. He's able to write melodies over complex chord changes, and his lead guitar technique is accurate and tight, yet never forced. He has a lot of Django coming out of Trigger. And he's arguably "Great" because of his historical relevance and endurance. He's an icon, as is Neil Young, the difference being Willie can play circles around him and Young would fall over dizzy. Willie would then grab Hank William's Martin and run, righting one of the greatest guitar travesties of the last 40 years.
