https://www.redditinc.com/#section-4
Reddit discussion:
https://www.reddit.com/r/WatchRedditDie/comments/j4fsi1/redd...
Company history:
https://en.wikipedia.org/wiki/Reddit#History
From there, I suppose this is the rationale:
> The idea and initial development of Reddit originated with then college roommates Steve Huffman and Alexis Ohanian in 2005.
> Between November 2005 and January 2006, Reddit merged with Aaron Swartz's company Infogami, and Swartz became an equal owner of the resulting parent company, Not A Bug. Ohanian later wrote that instead of labeling Swartz as a co-founder, the correct description is that Swartz's company was acquired by Reddit 6 months after he and Huffman had started.
EDIT: This doesn't seem to be news though. Checking the Wayback Machine, Aaron Swartz seems to never have been mentioned as a founder on that page. Here's what the page looked like in April 2018:
https://web.archive.org/web/20180409192133/https://www.reddi...