I'm sorry, while its nice to be able to stick this into two very neat buckets, I think there's a whole host of believable explanations which fall between those two extremes.
Even the CTO of 10gen admits some of the complaints in the original rants are valid (the global write lock, sharding doesn't work well under load).
Even the CTO of 10gen admits some of the complaints in the original rants are valid (the global write lock, sharding doesn't work well under load).