Have to disagree here. No way a 65 yr old with a 20-25 tr life expectancy should not have a market outlook approach when making investment decisions. TDF's are a product that strives to give the illusion of managing assets. They are cheap and easy to create and distribute, protect 401k administrators from litigation and individual investors usually do not sue for under performance so the custodians are protected. But are they in the best interest of the investor, no. IMHO.
I would say an average 65 year old can only make a negative impact by adding any active input into his asset allocation decisions. Don't forget that these are the same people that can barely find the US on the map. Once we are talking about higher NW and skill, it's a different story.
You are right if investor is not getting any advice. I'm coming at it from a different (and somewhat biased) angle, I'm with a BD. If I'm doing what I get paid to do, I think I can create a better solution. Even after my 1% vig.
I think this is disallowed, if it follows the same index. SPY/VOO can be loss harvested with VTI or other total stock market ETF's