Seriously, there is a lot of judgement in that sentence.
"Having a life", having a family is a matter of choice. I can choose not to have a family and work on my pet projects. I choose how I spend my time. If I sacrifice relationships in favor of pet projects, does that make me a lesser person? could it possibly make me a better software developer?
Is it really unreasonable to imagine that there are many talented software developers in the "lifeless" set of people with pet projects? Perhaps the author is of the opinion that the set of people with pet projects have higher ratio of talent compared to the full set. That is not to say that there are not passionate talented people without pet projects.