> On average, who's going to be better at writing code, the one who has done a side coding project in the past 10 years whilst developing, or the one who hasn't but only worked a job?
You’re clearly leading toward the former, but I could just as easily make an argument for the latter.
In my experience, people with edifying jobs (usually because the problems are harder), are less likely to need to scratch the same itch outside of work.
I think requiring side projects not only shrinks the candidate pool, but also leads to adverse selection.