Basho has always had an issue with the way Mogno was architected and marketed, and they have no issue with letting people know. (several blog posts, killdashnine parties)

I actually like both Mongo and Riak. I think they both solve a different problem set, and can actually complement each other in a polyglot persistence setup. It's a shame that there has to be so much negativity between them, because at the end of the day, this type of whiny blog post doesn't really help anyone.