Define "ruthless". If it means making the hard decisions (like you said "we don't want to give up his current job" - that is a decision), then yes, absolutely, a person HAS to be willing to change, move out of the comfort zone, try new things, follow the dream/plan/goal, MAKE the dream/plan/goal, take risks within reason, learn enough (not usually school) to do a proper risk/reward analysis on any decision, etc, etc.
If "ruthless" is defined as "user", then no, this person may achieve short-term success, but wastes the capital necessary to really achieve in life.
As far as sacrificing family - I believe I read in a study at one point that the top 5% of people are usually (over 90%) with their first spouse, happily married with children. (It was a study of corporate CEO's.)
For your friend with the grade 8 education and the moving company - admittedly, the decision the company made hurt her. Is she "ruthless" enough with herself to move on? To move out of the mindset she is in, to make whatever sacrifices are necessary to get to where she needs to be? A woman in good health at 55 has a very strong statistical chance of living to 90+. She has over half of her working life left! Sandra Day O'Connor - she was HOW old when she went back to school - and went on to the Supreme Court in the course of her career?
So "ruthless" - yes, absolutely, WITH YOURSELF.