Business income is volatile. The business made a $2B profit in one particular year, whereas in other years they made losses that nearly destroyed them. Somehow I suspect when the business took losses, the employees did not return their wages.
Unless you want employees to share the downside of business income volatility, it's unreasonable to expect them to share the upside.
Unless you want employees to share the downside of business income volatility, it's unreasonable to expect them to share the upside.