Depending on your location and the amount of opportunity may ultimately decide which side of the fence your on.
For me, understanding why a tool/framework exists and the problem is solves is much more important than understanding how to use a specific tool/framework.
Anytime the hiring discussion comes up, I am always reminded of this. While do people classify themselves this way in a resume? Django Developer? I guess if you only want to develop in Python using an MVC framework, then sure. But doesn’t this tend to lead to “When all you have is a hammer, everything looks like a nail”.
The understanding of a pattern or practice is transferable between programming languages and frameworks. NHibernate or Entity Framework? StructureMap or Unity? Who cares! You probably won’t touch the delta anyway.