I actually bothered to read the article.
250 people got to vote. 30 of them, ie over 10% were Rolling Stone employees.
They select the people who vote, so by tweaking the make up of the electorate you can come up with any result you want.
Here is the list of who actually got to vote,
https://www.rollingstone.com/music/music-news/500-greatest-songs-voters-list-1225358/
The vote was also weighed but they don’t really explain how the weighting works, but each song in the list was awarded a certain number of votes, not just 1-50 as you might expect.