Fair question. I think 'depends' has different connotations if you are talking about a binary outcome or function.
If I were to say something like "life depends on water", the connotation is that water is a necessary condition. You wouldn't use depends if the dependency is situational e.g. "life depends on shoes". Shoes might be the difference between life and death in some situations, but irrelevant in others.
That is to say, if a factor is a poor predictor of the outcome, but perhaps correlated, depends seems misleading.
Got it. I am talking about a function, and particularly the expected reward function for a behavior. If some factor has no influence on the score, the function does not depend on that factor. If it does, it does.
Even in your sense of the term, I think I was correct to say that HN "depends so heavily on the upvote". It's a fundamental constituent of how this place works.
But I'd also argue that even in the person I'm replying to later in the chain, it's a reasonable thing to say "describing a reward function that depends on the upvote" with your sense as well. If a person just wants to write, they can write in their journal or type in the reply box and then just close the tab. I do that sometimes here. If they actually click reply, then it's pretty clear their expected value for that involves somebody seeing the text. And the amount of that visibility is strongly determined by the upvote.
If I were to say something like "life depends on water", the connotation is that water is a necessary condition. You wouldn't use depends if the dependency is situational e.g. "life depends on shoes". Shoes might be the difference between life and death in some situations, but irrelevant in others.
That is to say, if a factor is a poor predictor of the outcome, but perhaps correlated, depends seems misleading.