Actually that's brilliant. Forget about the transition period for a moment, what do we want the industry steady state to look like. And I think it's exactly this. You are licensed and trained to work with personal data. Your license is on the line for misuse. You have all the incentives in place for the right behavior, and companies have the right trade-offs to consider when choosing to use it or not.
You can do tons of software development without needing personal data, and when you do need it you have someone in place who is accountable for it.
I know that needs fine tuning and it's out of my wheel house to nail down, but it's something I'd like to see.
The other thing to note is that certain jobs can be easily offshored. If you can't get a local (data scientist/software engineer/ journalist) to do what you want, you can just pay a foreigner to do it. The same is not true of doctors and lawyers, due to the extra privileges you point out.
The author of this article did not seem to think about this too deeply -- the bar exam works because it grants extra privileges to those who passed it; and barber certification works because it is easy to tell barber from non-barber. Neither is the case for data scientists.
IMHO, if one wanted to add regulation in this area, the "working" approach would be to add restrictions first -- like only licensed people can work with personal data.
But then we'd have to worry about cases like "there is a team of 's/w engineers' writing the code and a single licensed person who can only press 'run' button". And fixing that would require even more regulations... which will probably transform the B2C software landscape, and it is not clear if it would be beneficial or not.