an employee is not taking risk "investing in time" in a company, because they are paid wages for it.

If it were the case that employees need to put in capital into the business before being employees, then it would be a different story. In fact, those schemes exist - they're called MLM, or multi-level-marketing schemes, where you pay the company upfront to buy the product, and try to sell it at a profit (like herbalife), and try to recruit on behalf of the company!