Because most people don’t live their life by min-maxing their finances. They have other non-financial objectives that take priority over being efficient with money. You might as well ask why people buy nice cars, eat out at restaurants, etc. If people optimized for financial efficiency then the world would look very different, and the median household in the US has a lot of cash leftover to burn even after accounting for ordinary lifestyle expenses (~$12,000 per year, per the US BLS). Seattle, of course, is much wealthier and higher income than the US median so there is more money to burn.

That said, most people struggle with financial and investment math generally, even when they sincerely attempt to make prudent financial decisions. I can’t really blame people for not knowing how to build and reason about financial models, it isn’t a skill you ordinarily pick up in day-to-day life.