Fair point, although I wasn't assuming any bad intentions, more like a hard-to-explain emotional intensity that seemed out of character for someone whose writing I am familiar with. But perhaps expressing my genuine surprise was not constructive—thanks. I removed this intro from my post.

I found this reply unpersuasive.

By numerical point:

1. Speculation on OP's education is irrelevant. You reject lots of studies by PhDs that did study the field. If she misunderstood something, address the specific error.
2. Deep skepticism of the sleep literature is fine, even if you rely on some sleep research yourself, but it's insufficient to respond to the objection of hypocrisy of relying on the sleep literature with "well, I'm really careful about which studies I use". You need to explain why the studies you use somehow avoid the methodological problems that cause you to reject other studies. If you don't, it seems like you are just cherry-picking supporting studies because they support you.
3. It is SO strange to me that you rely so heavily on your personal experience, which is almost the least reliable scientific method available. Who's to say that your experience generalizes? You're a very unusual person. I'm always incredibly skeptical of people who have the position "everyone else's introspection is unreliable, but somehow I'm above all of that" or "you are all brainwashed by consensus, but I can figure out what's true and what's BS because I'm smart, educated, and careful".
4. Your claim here relies on an apparent failure to seriously consider the gap between ordinary language and scientific claims, which is a gap I'm confident that you are aware of in other contexts: "I think that the very fact that acute sleep deprivation sometimes increases energy and mood should make almost everyone almost completely re-evaluate everything they know or think about sleep because this should just not happen under the "sleep is restorative and is necessary for good functioning" paradigm."
   Here's the thing. A common error in science articles is using a non-standard, specific, operationalized definition for a concept in the actual study and then using an ordinary language meaning for the concept in the conclusions, leading to overgeneralization. IF science were formal logic, then yes, one counter-example should cause us to reject a general proposition. BUT, science articles that say "sleep is restorative" aren't claiming "sleep is restorative in every case for every person on every night", they are making a claim about average population effects. THUS, the fact that acute sleep deprivation sometimes increases energy and mood should not make us think that we must reject everything we know about sleep. This also responds to your no-of-1 proof by contradiction point.
   An analogy: cold weather makes us feel cold. The fact that people suffering from hypothermia will, just before death, suddenly feel super-hot and take off their clothes doesn't mean that we should reject everything we know about weather and subjective temperature. It means that a general probabilistic claim doesn't always apply. That's why I'm not persuaded by your personal experience. You live a super atypical lifestyle. Your experience makes me think that reduced sleep times is something worth studying further, but doesn't make me reject existing findings.
5. Some is addressed above, but I am just floored that someone who is skeptical of much of published science due to methodological problems is so willing to be persuaded by "trusted personal experience" and "trusted anecdote". I agree that we should be much more skeptical of popularized scientific findings due to valid methodological criticisms, but the solution is not to embrace lousy methodology. If we embraced trusted personal experience and anecdotes as reliable methods for truth findings, we lose the ability to reject massively harmful alternative medicine and new age movements that are propped up by them. The whole reason we set up scientific methods such as systematic data-gathering and double-blind trials is to prevent self-deception.
6. Again, re: the default claim "sufficient sleep is good and necessary for proper functioning for normal people on the scale of a few days to a week", this is not a formal logic claim about all cases, it is a claim about trends and norms. And I am not convinced that the default claim is limited to the scale of a few days to a week, but is instead about sleep in general.
7. I have no comment on this!

Hi, I'm new to this site so not sure if late comments are still answered...

The issues you raise overlap with relatively recent enthusiasm for discussing "natural kinds" in philosophy. It's a complex debate, and one you may be familiar with, but the near-consensus view in philosophy of science is that the best account of scientific categories/concepts is that concepts are bundles of properties that are/should be considered natural kinds based not on whether they are constructed or natural (a false dichotomy) but based on whether these concepts are central to successful scientific explanations. "Scientific" here includes philosophy and any other type of rational explanation-focused theorizing, and "success" gets cached out in terms of helping with induction and prediction. So the usefulness that you ask about can be grounded in the notion of successful explanations.

Here is a paper that discusses, with many examples, how concepts get divided-and-conquered in philosophy and science: https://doi.org/10.1007/s13194-016-0136-2. One example is memory—no one studies memory per se anymore; they research some specific aspect of memory.

Author, let me know if you want references for any of this.