You are right, head hunters nowadays seek for programmers fluent in Python, C#, Java, but never in Assembler. Don't give up, a good company won't restrict developers to the one particular platform (though it might be easier for them to maintenance projects then).
In my job I am expected to solve problems, not to write a solution in some concrete company-preferred language.
When you master an assembler, you still could make a fortune writing drivers for hardware, analysing foreign code in antivirus company, hunting for bugs created in higher programming languages by your colleagues.