Agree that investments need to be more conservative as you approach and enter retirement.
But keeping significant money in cash seems like a bad strategy when even AT retirement you're still looking for your funds to hopefully grow and last 20-30 more years if you need them to. Which is still a long term timeframe
You still need long term growth. You just need safer flavors of it. To me that screams 'less aggressive target funds', not 'piles of cash'. YMMV.