How tiring. We can litter the internet with posts like this, but it would be a
lot more useful to post reasoned, factual and detailed posts when discussing the merits or pitfalls of a given technology.
I've launched very high traffic websites using MongoDB, where it was the least of my worries. I've also launched very high traffic websites using MySQL, where it was my primary source of pain.
Shall I now run around screaming loudly about how badly MySQL sucks? On the surface you might assume so, but with reasonable effort to consider all the facts, it becomes clear that there's more to this than just "this database is better than that one because I hate it."
This post is more of an angry payback rant from someone who got banned from IRC for being abusive to newcomers and greenies. On top of that, it is factually incorrect in some spots, and misleading in others. Not impressed.
That said, NoSQL databases are evolving extremely quickly, and have reached a point of maturity that they can excel in the right scenario. Just like relational databases, they can provide big benefits, given that the user takes the time to learn how to use them, as well as making sure they have a use case that merits the strengths of their chosen tech.
I really enjoy working with MongoDB and Redis, and have been a community cheerleader of sorts for PostgreSQL for years. It is possible to have multiple tools in your toolbox, and use them when appropriate. No tool is perfect, and no tool is perfect for every job.
Complaining bitterly that your shiny new piano makes a lousy boat, on the other hand, simply adds to the noise.