This is describing two stages in the growth of programmer skill. The researchers are at beginner stage and make classic beginner-stage mistakes. The developers

This is describing two stages in the growth of programmer skill. The researchers are at beginner stage and make classic beginner-stage mistakes. The developers are at intermediate stage, and they make classic intermediate-stage mistakes. There is a later stage of people who can avoid both, but the author probably hasn't worked with anyone in that stage. Which is not surprising, because once you're that experienced there are big financial incentives to get out of academia.