I'm not sure I understand what the real dilemma is here of working for a startup. Being employee #15 is not the same as being in the first 5 hired. You don't take the same risks (or even do the same type of work), so there is obviously less reward when it's time to exit.

If you want to get rich, the best way to do it is to start a company yourself - but it sounds like the author didn't want to go that route after trying it. That's OK though, it's not for everyone. But I think the author needs to understand the risk-reward thing here a little better - you need to take more risks to earn more reward, and being the 15th hire at a company that has most likely already raised money is significantly less risk then being like employee #3. A lot of companies compensate their first handful of employees in equity a lot more than others because they took risks (and pay cuts) plus made contributions to the growth of the company that that employees #10 and after most likely didn't.

It still makes perfect sense to work at, or start, a startup - you just have to have the right appetite for risk and the right mindset for the varying types of work you'll be doing (compared to latter employees who can specialize more). You simply won't get "rich" without taking the risk and accepting that you have to broaden your capabilities beyond core technical skills to grow at a startup and earn your way to a nice exit package.