Yeah, I seem to have heard this somewhere before.
But you're missing the point altogether.
If you have $100,000 the day before the 2008 crash, and the next day, you lose half of that value, you have $50,000. Even if you don't plan on using that money for decades, that $50,000 you lost is gone forever. Sure, in the following years you might make it up, but you will NEVER see the lost $50,000 again. That money will never again gain any interest for your retirement accounts. The potential compounding interest that $50,000 would have gained, on top of the $50,000 you still have, is gone forever. You lost that $50,000 and all of the money it will have ever earned.
The same concept applies if you lose half of your 401k in a divorce. You might make that loss up, but that half is gone forever, never to be seen again.
Now, you can chalk it up to "the market", and that's fine, as far as it goes. But let's not pretend our stock market system is a level playing field for all participants, or that it follows the "free market rules". It doesn't. It is a rigged game for huge players, and Main Street players are just vying for the leftover scraps. If the free market were run on neutral laws and rules, there would have been no bailouts. All of the banks that took ridiculous risks would have died a natural, deserved death. Wall Street banks play with house money, and you and I play with our savings. When Wall Street loses, their losses are socialized, and every taxpayer is on the hook. When you and I lose, we work until we die, if we're still lucky enough to have a job.
That's why a company or union pension is a good way to retire for working people. But when Wall Street has all of the money, they control the government and make all of the rules. So they can rig the system where it's okay to under fund pensions and have the big ratings companies, like Moody's and S&P can tell big pensions that Mortgage Securities are AAA rated and safe investments for them, as required by law. Even when they know those securities are built on a house of cards.
Wow, big surprise, then, in 2008, those securities came crumbling down, dragging pensions funds of all types and stripes down to the crapper. Well, at least the banks that made those securities and the credit agencies that stamped them AAA were prosecuted to the fullest extent of...oh wait, we're still waiting on that one. And one of great ironies of the housing crash, was Moody's, downgrading states and cities all across the country, because their finances were falling apart, in large part because of their AAA rated investments were taking a big dump.