There are plenty of reasons not to code on spare time. If anything the people who are most likely to do that are often also the people who coding interviews are supposed to be privileging, fresh single college grads.
I don’t know how people would square the statements “take-home assignments are unpaid labor and unfair to people with time commitments” and then do a 180 and say “people should have an up-to-date fresh github that they work on in their spare time.”
If you went to college but never made anything, that's a signal.
If you didn't go to college, and never made anything, just shut up and make something.
At the end of the day, it isn’t really relevant to the employer what is done in spare time off the job when they get hired, so it’s not like I should privilege their spare time projects over people who don’t do that, particularly if people don’t want to code off the clock. There are plenty of good engineers who do not code off the clock, and there are plenty of bad engineers who do.
Also, more often than not, coding off the clock for the sake of having a portfolio is not really indicative of anything. There aren’t, for example, review processes or anything like that in a one person side project, and unless I spend significantly more hours background checking who’s to say the side project is not plagiarized? People already lie on their resumes today.
Some people have more trouble completing tasks for reasons that have nothing to do with talent or intelligence.