Yes: you can specialize in being a really good programmer for a particular platform. I have a lot of friends who specialize in being Serious Engineers, who understand how to get interesting and important things done with lenses and how to effectively get a whole project away from null pointers and into monadic error checking and how to use type systems to prove programs mostly correct as they're being written.
That is a real specialty. It takes real skill and investment of time to get to the point of being expert with that stuff. I'm not diminishing the value of being an expert software developer.
I'm just saying that basket of specialties is unlikely to command a very high wage premium, not because it's unspecialized, but because it's hard to fashion a value proposition for it relative to your competition in the market.
There will be times during which particular platforms or languages will get hot, and it'll be good to be expert with them. But (a) those phenomenon will be more transient than other problem domains, and (b) the wage premium for being specialized in them will still probably be lower than the wage premiums for the other domains.
At any rate: as long as you're thinking about the domains you're specializing in and not a career as a "programmer" or a "builder of software", we can probably agree to disagree about the rest of the details.