I suspect there are people who'd write features and who would attract a lot of interest, but I think you have to take your announcements to more widely read spaces or directly solicit people you think might be interested.
This, and I think it also applies to readers just as much as writers.
chooseusername, I remember when you approached me some time ago about writing something, and then (as well as more recently) when I go to look at IR there is pretty much no evidence of a readership. Not that there isn't one, but it's not at all obvious that anyone reads the articles. Nor is there any interaction surrounding the articles, which would be a primary indicator that they're being read.
As is, there seems to be more value in putting articles like this on a blog where users can at least comment and interact with the author and between themselves. I recall you set up a subreddit where people can discuss the articles, but I never saw any discussion. It doesn't help that the location for discussion is detached from the articles themselves.
It's hard to attract writers without an audience. I know, catch-22 about getting readers before writers... but previous issues had quite a few articles yet there wasn't really any discussion then, either.
The marketing aspect, while probably not something you're interested in, is kinda necessary to keep something like this alive, which would also be easier to accomplish given a better format. I like the way IR looks and feels, but it doesn't seem as practical on the modern internet.
...just me speaking as a potential contributor about what keeps me from contributing. Some writers write purely for the pleasure of writing, but I believe a majority would prefer being able to reach the widest audience possible, or possibly even interact with that audience.