I've seen it repeated multiple times, and in the past have even repeated it myself. But these days I'm not so sure. I think you should go into it being ok with the possibility that it'll be worth zero, but I don't think you should plan for it to be worth zero. Put another way, I don't think you should evaluate competing startup offers completely discounting the equity comp. A company that offers $200k and 0.05% of itself is not automatically worse than a company that offers $250k and 0.01% of itself. Hell, that's still true even if they're both offering the same equity ownership percent.