> The vast majority of cases stock options end up worthless
Also, even if the company ends up worth a lot of money, there's no guarantee that a way to liquidate, such as an IPO, exit or secondary market, will become available in any reasonable time frame. And as a regular employee you have exceedingly little to say in bringing about such events. There's not much fun in having a winning lottery ticket that can't be cashed in, in fact it's highly stressful.
Also, even if the company ends up worth a lot of money, there's no guarantee that a way to liquidate, such as an IPO, exit or secondary market, will become available in any reasonable time frame. And as a regular employee you have exceedingly little to say in bringing about such events. There's not much fun in having a winning lottery ticket that can't be cashed in, in fact it's highly stressful.