And that happened, IMHO, because the people behind reddit didn't behave like jerks and the people behind Digg did.
One example of being jerks: http://blog.jgc.org/2006/07/sense-of-humor-failure-at-digg.h...
After that I was unbanned, but not after an employee of Digg defamed me in a blog post by making false claims: http://blog.jgc.org/2006/07/unbanned-from-digg.html
And here's an example of how reddit people weren't jerks when I inadvertently brought the site great slowness: http://blog.jgc.org/2010/09/tale-of-two-cultures.html