Shady? Yes. Dishonest? No. To be sure, both of these attributes suck, but beyond that there is an absolute world of difference between the two. One passively leaves knowledge gaps that even novice consumer programmers would uncover (the source is wide open after all, and speaking from personal experience, any claims of hyper performance should arouse enough suspicion to inspire some basic research), while the other asserts no knowledge gaps and actively inhibits knowledge discovery.
That said, they fell very far form the ideal, and for that they should be faulted. They're now paying the price by living in a dense fog of distaste and disgust. I don't think anyone believes it's a "statistics fluke" but it's a likely that a mob/tribal mentality plays some role (this is an industry notoriously susceptible to cargo cults) and that many individuals on the burn-MongoDB-at-the-stake bandwagon do not actually have deep--or moderate!--experience with it and competing products. Also, would you chalk it up to statistical anamoly that they were able to close funding and that many large scale systems use their product?
Isn't it possible that the company had shameful marketing practices that repel the programmer psyche, but that the product itself has a unique enough featureset (schemaless yet semi-structured querying, indexing, dead simple partitioning and replication, non-proprietary management language, simple backups, all at the cost of RAM/SSD) to make it compelling for some problem classes?