It's a false dichotomy that you either have to let your kids starve or support evil companies. Again, it's this dichotomy that has led to the present situation.
But your false dichotomy ignores reality, sure he could leave his current job (assuming he can't ditch evil company X at his current job), but will he then find another job at an "ideal" company that is a) not evil and b) uses no evil companies products, probably not