I think you are misreading the point. It's not that the true expected value of early stage options is actually zero, it's that it might as well be for your purposes, choosing between that and other reasonable (i.e. market value) opportunities.

If you look at early stage startups, I think it's pretty clear that the EV[startup options] < EV[invested market value salary delta]. This holds true over nearly all startups, and nearly all people who have the option of early stage options. There are outliers, sure - but to a 1st approximation you aren't in them.

So you have to fall back on "how much more fun/cool is this startup job than other things I can do". And realistically, getting rich off a startup isn't a rational plan for nearly all people. Asking yourself, "what are the odds I recoup most of the lost salary?" is a more like it. And for typical seed round start up, that break even is going to be a few percent, dilute as needed to look at different rounds.

Of course this doesn't help you choose between two different under market salaries with options, either...