> Why would a person with 20 years of experience want to work for a company with no work-life balance?
The initial comment by bfieidhbrjr already answered that very nicely: out of the desire to actually do something that is important re work. Important being subjective to the person in question obviously.
A lot of people already work meaningless jobs with no work-life balance and they would find it to be a substantial improvement to work somewhere with meaningful work even without a proper work-life balance.