They got paid for it in the form of money and stock.
If the stock is worthless, why offer it? The answer to me is obvious, they are being deceitful (the start up and its investors). As stated, the SECs' mission is so that people who deal with securities don't engage in deceitful behavior, since deceitful behavior removes trust which creates friction.
The argument that people's rewards, one who put in $50 in cash and another who and accepted a lower payment/higher risk which resulted in a decreased earnings potential of say $50 should be treated differently is anti-meritocratic. Both are risking $50.
BTW, if the company offered no stock to employees, we wouldn't be having this conversation. But the comments are, or should be, based on the FA of which this is a thread.