Spending little money frees up your life from having to earn a lot of it. That trade-off starts looking pretty attractive after you've been chained to a desk for a decade.
Having a high income doesn't make you rich if you just spend it all... By definition, being rich requires spending much less than you make, unless you inherited it. Whether that counts as "penny pinching" is a different matter, but the ability to live within your means is certainly accessible to most people if they're willing to delay gratification.