> There's usually not a relationship that goes the other way though, for example, developers don't tell DBAs to pick up code so they can write the models in our language in addition to the underlying SQL. This highlights a trend of increasing responsibilities pushed onto the developer.
Yes, because as a developer you're the one who has the responsibility of implementing the business requirements of the app. There's no trend here; this is the way it's always been. The buck stops with development for a lot of things. The developer is in a unique position to respond to many incidents because they have an intimate understanding of how the business requirements wed with the technology in ways someone like a DBA does not.
DBA's have plenty of responsibilities of their own, such as handling a 3AM alarm that goes off when some part on the application starts hammering the DB from some poorly designed N+1 query problem in the codebase. Often times when the DBA tries to teach the developer it's because he's sick of getting those 3AM wake-up calls.
> But in some cases it's specialists designating what an expert developer should know. It's giving away control in some respects. This turns into new job requirements and a higher barrier for entry. The growth will need to stop at some point.
That's a strange mindset to have. Different jobs have different technologies, and as a developer you learn how to work with them. The specialists aren't designating anything, the job you're responsible for is.