One possible explanation for the lost appreciation of SQL among developers is the increasing popularity of object-relational mapping tools (ORM) that generally tend to reduce SQL databases to pure storage media (“persistence layer”). The possibility to refine data using SQL is not encouraged but considerably hindered by these tools. The result of the excessive use is a step-by-step processing by the application. Under this circumstances SQL does indeed not deliver any additional value and it becomes understandable why so many developers sympathise with the term NoSQL.
.. But the problem is that the term NoSQL was not aimed against SQL in the first place. To make that clear the term was defined to mean “not only SQL” later on. Thus, NoSQL is about complementary alternatives. To be precise it is not even about alternatives to SQL but about alternatives to the relational model and ACID. In the meantime the CAP theorem revealed that the ACID criteria will inevitably reduce the availability of distributed databases. That means that traditional, ACID compliant, databases cannot benefit from the virtually unlimited resources available in cloud environments. This is what many NoSQL systems provide a solution for: instead of sticking to the very rigid ACID criteria to keep data 100% consistent all the time they accept temporary inconsistencies to increase the availability in a distributed environment. Simply put: in doubt they prefer to deliver wrong (old) data than no data. A more correct but less catchy term would therefore be NoACID.
Deploying such systems only makes sense for applications that don’t need strict data consistency. These are quite often applications in the social media field that can still fulfil their purpose with old data and even accept the loss of some updates in case of service interruption.
.. One might believe the success of NoSQL is also based on the fact that it solves a problem that everybody would love to have. In all reality this problem is only relevant to a very small but prominent community, which managed to get a lot of attention.