Unless one literally does not care about computers AT ALL, and is content with front-end development, having no hobbies involving any OTHER kind of development etc, one will end up being a bit of a "full stack developer".

I, frankly, don't trust career coders who don't have an active interest in the broader activities around coding, software, hardware, maybe HDL's and FPGA's, or low-level stuff with microcontrollers etc.

as it appears that a career coder who specializes and then expresses no further interest in branching out is merely milking a perceived cash cow and not going to show an interest in how even the specialized piece they are building inter-relates with the other pieces of the puzzle.