The languages Adam speaks of seem to  be in low demand, I suppose that's the reason not many people bother to learn them.

An interesting article caught my eye at jobstractor.com — the programming language trends review. The company analyzed more than 60,000 job vacancies during 2012 to produce a chart of the most sought-after technologies:

Language	Jobs
PHP	12,664
Java	12,558
Objective C	8,925
SQL	5,165
Android (Java)	4,981
Ruby	3,859
JavaScript	3,742
C#	3,549
C++	1,908
ActionScript	1,821
Python	1,649
C	1,087
ASP.NET	818

Despite developer complaints, demand for PHP and Java (server/Android) remains strong. You would also expect those jobs to require some SQL knowledge although that has a strong showing in its own right.