It has more to do with the fact that Twitter, much like 4chan, is a terrible hell scape that needs to be wiped off the face of the planet, but has played host to the creation some of my favorite content the Internet has to offer.
Reddit, on the other hand, always felt like a dusty mirror to older forum posting, a centralized location of all the dumbest, rudest and most psuedo-intellectual people who couldn't hack it on the actual expert forums. A glorified reposting site.