"NoSQL is widely taken to be a joke by professionals, who can easily achieve the same scalability using relational databases, without giving up their many useful and even necessary features." - I have a problem with this comment. Happy to agree that so far anything that's been publicly demonstrated indeed has been just an exercise in breaking ACID for no reason, but relational databases have their limits as well. So yes, NoSQL movement is a joke, but relational databases aren't necessarily the safe haven as they may seem.
For background: Just this afternoon company I work in lost around USD 500k (estimated) just because our relational database is working hard at the limits. We are one of the reference cases for the vendor.