Mega-Roths and Young-Guy GRATs

Once you create a self-directed Roth IRA (probably by converting your old regular IRA) your goal should be to invest for as much growth as possible. In Forbes Deborah Jacobs tells how Silicon Valley entrepreneurs, using shares of their own companies, are parlaying this strategy into mammoth tax-free capital gains. She also notes an interesting trend for young tycoons to set up GRATs even before they've started a family.

Should the use of Roth IRAs to shelter unlimited wealth be curtailed, as Jacobs proposes?