The risk isn't zero, and the benefits are usually subtle at best. On the other hand, mountain-climbing also has risks, and is so devoid of benefit that the only excuse mountaineers can come up with is 'because it's there'.
Madness string 82052
I'm also the type that, if someone came to me and suggested moving off of a relational dbms to mongo, I would give them a large cactus and instruct them to use it as a suppository.