Every A Player I've ever worked with has brought full attention, quality and focus regardless of other priorities in their life (barring major, extenuating circumstances like a death). What they do in their non-work time has little impact on their work productivity unless it starts causing too much sleep deprivation.

Most people I've met can handle thinking about more than one thing in a given day or week and to be a productive human you have to. Whether it's reading a bed time story to your child, remembering what groceries to buy on the way home or checking the code a friend committed to your side project, you have to think about other things besides work every day to be a normal, functional human.