By failing to make active decisions about their plans allocation, they have been auto-enrolled in TDFs and thus are more heavily exposed to equities than seasoned investors.
If you want to see a template for the retirement plan of the future, check out the Secure Choice Savings Program enacted by the Illinois legislature in December.
As the financial industry gears up to stop or alter the rule, the fight actually may be less about fiduciary duties and conflicts and more about costs and loss.