Amen. After working at Amazon for three years and seeing plenty of relational and non-relational storage engines in very large-scale production use, the #1 lesson is that both are scalable, both are useful, and each is a better fit for certain problems.

I agree that relational databases are often applied to problems where other systems would be better, and we should work on studying those other systems, improving their implementations, and educating engineers about their use. But we should be "pro DHT" or "pro document store" or "pro column store", not "anti SQL."