An extended exercise window is not an end-all-be-all solution. Other solutions that don't have the dead equity problem include:
1. Actually pay startup employees reasonable salaries and don't pretend their equity is 100% certain to lead to great riches since it is a risk
2. IRS / Congress could fix tax treatment in this situation, since it is not serving the purpose it was intended to (avoid rich people dodging taxes)
3. Startups actually IPO / get liquid faster instead of contributing to our existing private equity bubble where liquidity events are delayed indefinitely, rendering equity useless. More liquid cash flying around is generally better for everyone as long as it's not a dotcom-era bubble.
Employees have just as much of a responsibility to learn this stuff as their employers do to act generally ethically. They're your employer, not your parents.