The page on the MongoDB site gives a 404.
MongoDB's strengths are also its weaknesses.
It doesn't care about the design of its collections. It'll punish poor design with poor performance but it will let you stick your Grannies fruitcake recipe in a collection intended for numeric data. It is faster and easier to make changes because it stores/retrieves JSON as the app would use it. This is great for the app and people with an in-depth knowledge of the object model generating the JSON. Not so Great if you are a bulk data consumer tasked with using data from a MongoDB. Software archeology has to be taken to a new level.
Skilled and disciplined developer's will come up with a good object model, good separation of collections based on the objects they are intended to store and good collection design. But there is nothing to stop someone using a collection to store objects of different types.
In the early days claims by MongoDB for what the product could do were hyperbole. I spoke to one consultant who said "yes, you can scale out and shard but please don't, it's a nightmare to administer and recover. If you can get away with it just scale up"! Far from being"Humongous" this limited the max DB size that would work reliably was 640Gb.
MongoDB is a great little system but your article draws attention to behaviours that destroy trust. We all know that salesmen accentuate the positive. Would you buy from a salesman who makes statements about competing products that are derogatory and you know to be patently untrue?