Doing free software work in one's free time is not the same as not having other interests. Besides coding, I do animal rights activism, read a lot, play go, watch films, hang out with friends, etc. So yes, if the only thing the person ever does is code, that might be problematic. OTOH, if coding is purely a day job, and not something they enjoy enough to do in their free time as well, they probably aren't going to be as good a coder as the person who pursues it out of sheer interest.