I think one big factor is universal relevance. Meta stuff about writing on Medium is, by definition, of relevance to everyone who writes here (though not readers more generally). We know that behind the headline, whatever slant it may take, there is a discussion of an issue that means something to us, and it will be presented in more or less a predictable style.

But any give piece of fiction or poetry is likely to strike a chord only with a small proportion of the small proportion of users who have an interest in either genre.

If I walk into a bookshop and go over to the 'fiction' or 'poetry' shelves, I can almost guarantee that I will hate 90% of the titles on offer, though I might love some of the remaining 10%.

I think it's this 'acquired and personal taste' aspect which makes it a hard sell for writers - and also the algo. If I label the tag 'poetry' as being of interest, and have a 5% read ratio of the poems that the algo serves me - without any filtering of the style of poetry, because it is incapable of that - what data does that give it? Those 95% of rejected poets are crap? All poetry on Medium is crap? Those would be the logical inferences for a crude recommendation system, I suspect, which is what we are dealing with here.

I'm not sure there is an easy solution - though being able to subscribe to publications, and having the possibility of grouping fiction and poetry pubs under an umbrella title that you could subscribe to, would help.

If people followed pubs that tend to publish their kind of stuff that also works - but hardly anyone uses their 'Following' tab, and trusts instead in the 'For you' algo function.