Thanks for unpacking that.
However, your argument is too fully general:
If the advice "do not get divorced" is considered sufficiently important and divorce rates are sufficiently high then it would follow that all else being equal "do not get married" is good advice.
If the advice "do not get in situation X" is considered sufficiently important it would follow that all else being equal Do whatever it takes to minimize the chances of getting in situation X is good advice.
This also applies to "kill yourself asap" being a good corollary if "don't eat too much marmalade" is considered sufficiently important, all else being equal. Strictly true, yes. Useful, no.
We have to acknowledge that these pieces of advice do not live in a vacuum where we can consider various values for their relative importance while keeping all the myriad other goals constant. That's not "carving reality at its joints", as the expression goes.
There are incentives to getting married, and without weighing those "do not get married" cannot be a general corollary of "do not get divorced" except in a spherical cows kind of scenario.
However, your argument is too fully general:
My argument included disclaimers that you evidently missed.
This also applies to "kill yourself asap" being a good corollary if "don't eat too much marmalade" is considered sufficiently important, all else being equal. Strictly true, yes. Useful, no.
I reject the reference class.
This is an extension of a comment I made that I can't find and also a request for examples. It seems plausible that, when giving advice, many people optimize for deepness or punchiness of the advice rather than for actual practical value. There may be good reasons to do this - e.g. advice that sounds deep or punchy might be more likely to be listened to - but as a corollary, there could be valuable advice that people generally don't give because it doesn't sound deep or punchy. Let's call this boring advice.
An example that's been discussed on LW several times is "make checklists." Checklists are great. We should totally make checklists. But "make checklists" is not a deep or punchy thing to say. Other examples include "google things" and "exercise."
I would like people to use this thread to post other examples of boring advice. If you can, provide evidence and/or a plausible argument that your boring advice actually is useful, but I would prefer that you err on the side of boring but not necessarily useful in the name of more thoroughly searching a plausibly under-searched part of advicespace.
Upvotes on advice posted in this thread should be based on your estimate of the usefulness of the advice; in particular, please do not vote up advice just because it sounds deep or punchy.