Why do we keep acting like we know what the requirements for life are? Those we look to for insight on this are most entrenched in socially accepted fallacies - oxygen is required, carbon is required, water is required.. and based on what evidence? We have a sample size of one - Earth. It's laughable that we're therefore so committed to defining requirements for life.
We don't really understand the mechanism that spawns life, so we can't say we understand its requirements.
Well, we've got some pretty good hypothesis about the mechanisms that spawn life, and we can extrapolate from there a little - though I do understand your point that we are burdened with an embarrassingly small sample size.
For instance, the alkaline thermal vent origin hypothesis stands up to scrutiny - it may well end up being wrong, but the other contenders are not so robust.
We know carbon is probably key, because of its properties, notably abundance and ability to oxidise (as Nick Lane, I think it was, quipped something like 'try growing a body with sand' (ie. silicon based lifeform)).
I think the surprise here is the assumptions made around multi-cellular / mitochondria / krebbs (ATP) were so consistently observed, that an exception really stands out.
Your tone suggests we shouldn't speculate about what requirements life has - but I don't think the intent is as full of malice as you appear to believe. I take it more as a curiosity meets a (prinerdial) need to catalogue everything, and then getting frustrated when things aren't so easily pidgeon-holed.
Implication is not explicit and therefore subject to each reader's interpretation. i.e. what seems to be implied to one's perspective may not actually be implied from all's perspective.
This kind of thing is implied in most science communication, every statement of fact has a "unless or until conflicting information is found" tied to it by common sense.
We also have samples of other nearby planets and astral bodies that do have signs of life. Signs, not evidence.
Mars, Enceladus, Titan, Europa, and some other places have signs that life might be present. Might be. Don't bet on any of them, but there is still a lot to be explored.
Lee Cronin is working on Assembly theory, which should enable measuring complexity in substances, with high complexity implying some life there. His interviews with Lex Friedman are pretty good.
We don't really understand the mechanism that spawns life, so we can't say we understand its requirements.