It's like being paid in IOU: "1% of this lottery ticket's winnings".

There's multiple layers of risk and trust, too many dependencies. The transaction is too complicated and takes too long to complete. So the probability for exceptions to occur is great, and handling for those exceptions will likely fail due to the complicated nature of the transaction.

%0.01 Because even if it's %1 at the time you join, by the time the lottery ticket can be cashed in it will be diluted, plus liquidations preferences, etc.

Or you take a discounted salary in exchange for stock, and after all is done you earn barely more than if you had just went somewhere else for full salary (if you are lucky you get that much).

Or you have a disagreement with your boss and leave, and while you are gone the company devalues the shares of everyone who left "because they aren't contributing any more."