Yeah I've also heard good COBOL developers can command huge pay on legacy banking systems. That would be a good reason to learn COBOL, but I don't think it makes COBOL a good technology choice.

There are times where NoSQL is a better choice. When massive scale is involved I understand that NoSQL can come into it's own. I'm sure there are other cases as well. But when it gets used for CRUD, it tends to be a bad call.

But there are so many comments in here saying that "SQL is hard" by comparison... should that not command higher pay?

They can command more pay because NoSQL is required by bigger companies who've got more clients and more money to pay DBA.

Also, NoSQL is not a database, it's 10 different databases which have little in common with each other. A rare speciality pays more.

And RDBMS developers can command even higher pay converting platforms.