I had go read section 409A. Sect. 409A would apply to deferred income even under todays existing rules. The 20 percent tax penalty applies when the options are granted at discount or the company valuation was considerably off from fair market value. Assuming the new law does not change rule 409A the point becomes moot. It will be the same tomorow as it is today.You are entirely missing the point. It matters a whole hell of a lot if I have to pay taxes on options the day they vest when I'm making $50,000 a year living in San Francisco and there's a non-zero probability that I'll never even exercise the options because the company won't be in business in 5 years, vice paying those taxes when the company IPOs and the I exercise the options into stock I can easily sell for far more than I owe in taxes. Startups don't think about taxes at all except the taxes they have to pay when they're in startup phase and every dollar counts as the difference between success and failure. This bill moves taxes from the realm of "wish I didn't have to pay so much of my windfall in taxes" to "can't do this job because I can't afford taxes on money I haven't made yet". Huge Huge difference in how people make decisions and outcomes for entire industries.
As for waiting for options to vest until they're sellable. First, read section 409A of the tax code. Generally deferred compensation is not only taxable but has an extra 20% tax penalty attached, and what you're proposing would clearly fall under 409A.
Second, I'm not sure you get the point of vesting. It's the primary mechanism in the startup world to reward longevity of effort from employees. You give an employee a decent set of options, and put them on a 3 year vesting schedule so the longer they stay the more of the options they get. Any options that vest are theirs to keep, even if they leave before 3 years. Your idea eliminates both the central tenants of vesting, so again why blow up what's worked so well for....wait a minute why are we doing this again? Because jobs?
With regard to deffered income. Today one could get paid in stock options and except for a few rare circumstances they are not taxed on that income until they excercise the option. Under the new rules they could be paid with stock options and they are not taxed until the options vest. Since we as owners and principles determine when the vest we simply allow them vest only after the company goes public. That takes care of the unregistered sale of securities mentioned by Sig.
One could argue that forcing one to pay taxes on deffered income earlier rather than later might be beneficial if the tax payer is in a lower tax bracket then they will be 10 years down the road. That would of course be specific to each individuals tax profile.
In short they are taxing the same income at the same rate. The IRS is just getting thier money sooner. I think this change will be very easy to write around legally and should have minimal impact.