@LLJB - you identified the crux of the matter that I was trying to address: "what return do you need, what's your risk tolerance and what's your time horizon?"
ISTM that investing for income is one response to this question. People in retirement need a certain minimum amount of cash monthly, they have a higher need for cash to more than barely get by, and beyond that want cash to enjoy their retirement. The more assured the cash stream is, the lower the expected long term result (and less money expected for that third tier - cash to have fun). That's what I was trying (apparently unsuccessfully) to illustrate with bonds.
I also mentioned annuities as a way to address some of the risk aversion. An annuity that pays out enough to meet just the first tier of needs (survival cash) can allay some people's concerns about having an adequate cash flow. As with most risk/benefit tradeoffs, that comes with the expectation of lower total returns.
Now to get into the weeds :-) One can remove reinvestment risk from bonds by purchasing long term bonds (say, 30 year Treasuries). If your retirement lasts longer than that, well, congratulations!
Would one automatically take the less volatile investment if two investments had the same expected long term returns? Not necessarily. Volatility is not identical to risk, and volatility (std dev) may not always be a useful figure. Since we're talking in the abstract here, I'm not going to worry about whether there are real world investments that behave as follows:
One investment returns 2%/month
50% of the time, and 0.0098%
50% of the time. You don't know which one for each month, but over the course of a decade it returns 230% (that's basically 1% compounded 120 times)). The other returns a rock steady 1%/mo, except for a random spike (down
50% one month, up 104.02% the next month).
The std dev of the first investment is 1.00 (since the monthly return each month is 1 ± 1). The second investment's std dev is 10.
53. Yet I'd take that investment. All I would have to do is wait out the dip (crash?) for a month and I'd have a smoother ride. Keeping a one month buffer is all I'd need.
So much of this is subjective. Given two investments that you somehow know will have the identical performance over, say, ten years, and you will not be selling over that period of time, their paths to that return (volatility) don't objectively matter.
Which gets us back to addressing sequence risk. Some people will bifurcate (or trifucate) their portfolio into buckets to manage that risk, drawing from the most stable bucket and disregarding the volatility of the other bucket(s). Others will prefer investments that try to temper downside movements. It sounds like KCMTX might serve them well, at least if it provides the downside protection you described.