That's precisely what I said.
You can transfer your own contributions whenever you wish - the free matching stock the company can give you if it wants to give you free stock cannot be transferred until it vests.
If your retirement plan is based not on your own investment but on the hope that your employer will give you enough free shares to enable you to retire, then you don't actually have a retirement plan.
I haven't seen a breakdown of the market value of Enron's plans, contributions vs. match, but I suspect the latter was a significant percentage of the total.