While I think you're correct that goals and roles may be different, on average, for the scientist-turned-programmer trajectory, there are plenty of RSEs who come from the opposite direction, i.e. strong programming background, but picks up the problem domain on the job.

Source: am RSE. And I will also say, a few of the scientists I support are among the best software engineers I have ever worked with, despite caring about code only insofar as it can help answer useful questions.