Do the RMD factors actually amortize an IRA balance to zero at some point? I ran it out to age 120 and there was still a balance. Very small, but not zero. And still fairly meaningful at age 100. So under your approach, how long do you assume the original owner lived for purposes of taxing the beneficiary?
If you work through a reasonably typical example... it's roughly the same answer as current law for a child of the deceased. Your approach does address the generation-skipping abuse. But the implementation might be too impractical. Seems to me, a more straightforward reform would be to leave current law (more practical) in effect for children and other non-generation-skipping, non-spousal beneficiaries (...I'm sure the IRS could come up with an allowable list of relatives... and/or age criteria relative to original owner). All others get the 10-year treatment.