Well some people belong at a startup, and then there are some people like you who clearly don't. Life shouldn't be all about the money, sorry to break it to you.
Startups are exciting and fun, but their success is gauged by a single metric - money. When startups get acquired there are endless congratulations on this very site. And rightly so, the owners should be rewarded for their work.
In the end I guess you're right. I don't belong at a startup as an employee making 1/2 my salary. I either need adequate pay and/or an equity stake to work at one.
Like anything, there's a reasonable-middle as to the salary requirements for an individual.