I agree with this, but for a different reason. Having specializations work for developers, not against. Consider all these technical lead sort of job openings

I agree with this, but for a different reason. Having specializations work for developers, not against. Consider all these technical lead sort of job openings in start ups asking the developer to execute everything from being archetecture to test/development to deployment. If you want to subject yourself to this, by all means, but keep in mind that there are developers who just want to go home at 5.