Distilling the meaning of this snippet from Lyn Alden's August newsletter:

"Just because the Fed cuts interest rates, however, doesn’t mean long-end rates (such as mortgages, corporate bond yields, or small business loan rates) will decrease. They might or they might not. Even if they do go down, I don’t think we’ll get a lower-low in mortgage rates, which will mean we won’t get a major US residential refinancing cycle which we normally get in response to Fed cuts. In other words, without a lower-low in rates, the positive consumer impact from them is likely to be rather lackluster."

Cutting rates may or may not result in lower long-end rates.

The Fed Funds Rate is an effective overnight rate for interbank lending. Its affect is primarily felt in short-duration rates. It is not upstream of long-term debt such as 20Y Treasuries, 30Y Mortgages, 10Y business loans, etc.

This is a common misconception and Lyn points out that alterations to Fed Funds (up or down) don't always result in the same directional movement of long term rates.

Long term rates have more to do with inflation expectations. If you are going to hold debt for a long period, you want to be assured that you are not burning your money away as the cash value loses purchasing power.

So, even if the Fed cuts overnight bank lending rates, there's no guarantee in a similar downward movement of long term debt interest rates.

If long end rates do come down, that doesn't guarantee a boost to the consumer economy.

A lower-low in rates would result in refinancing as, for example, mortgage-owners trade their existing debt for cheaper debt that is easier to service. This results in a cash balance that they can spend into the economy.

Lower rates without a lower-low compared to their existing debt means they cannot obtain this cash balance. The rates may come down, but on a relative basis they are still more expensive than the existing debt held by the individual.

This influences existing loans to remain in place, mitigating the potential for new cash balances to benefit individual's economic positions.