I think if a venture is unsuccessful employees shouldn't expect to make money from their options. A venture that raises $60MM and sells for $100MM 4 years later is a failure. Making nothing in a case like that seems fair to me. What is perhaps unfair, is if the employee worked for substantially below market wages all of that time, and particularly if they were given a much rosier picture than was accurate. But we shouldn't assume those things are always true.
I think the problem is that it's often difficult to pinpoint the crux of the unfairness, but still feel it all the same. In my opinion, the unfairness is engendered by the realization that time and money are merely different units of the same thing. Which means the investors are getting guarantees on their invested time, but the folks who did all the work are completely unable to recoup any of the time they invested. When we cast the investments in the same units, it clarifies the nature of the inequity.
Investors convert dollars into time (like a conversion from matter to energy), and workers convert time into dollars (energy to matter). Even in physics a seemingly small amount of matter has enormous power with respect to the energy it can unleash. But it can take a lot of energy to form the tiniest lump of matter. Investors are turning their matter, their dollars, into time. A lot of money, in that respect, is essentially lots of time -- more time than you have life, if you have enough of it. So you can do more, by buying someone else's time.
For simplicity, if we ignore non-labor costs (labor is the largest expense in most software startups, e.g.), it would mean that the invested dollars purchased an EQUAL amount of invested time. That is, the investors dollars were converted, with perfect efficiency to time (unless they overpaid the workers, or the workers were underpaid), which means there was conservation of dollars/time. This implies a balance of the two sides of the equation, which means at best (again, for simplicity, only accounting labor costs) the investors could only be guaranteed a share of 50% of the purchase of the company. Or at least that is how it should work, in my opinion.
If the worker is paid for their time, they aren't owed anything for it. If they are taking below market - as I said that may be unfair - then at most their investment is the delta to market compensation.
Also, investors puts in all the money upfront; there is a concept called time value of money that applies here, and what it means is that money paid upfront is worth more than a distribution of the same amount over time. The higher the cost of borrowing (cost of capital), the more valuable that upfront investment is.
If the investor is paid for their dollars, then they aren't owed anything for them either by the same logic. And they most definitely are paid. Investors are compensated for their dollars because they exchange those dollars for time, just as the worker exchanges their time for dollars.
Whether an investor puts money up front or not is irrelevant, as it is only converted to time incrementally as the time is traded for it. Any excess dollars in the bank can, and frequently are, returned to the investor in an exit. Hence they only trade in dollars to match what is invested in time (when only accounting for labor).
