We actually removed PDF export because there's no good libraries to handle PDF cmyk support.
My gut reaction as a programmer was: CMYK? How hard can it be? But then, I am no user of CMYK. All my experience is RGB, and in fact I am bad enough at color to not really notice it when color profiles are significantly off. CMYK is an unknown unknown for me, I don't even understand the troubles they are having.
So I think this touches a core problem of open source: The average hobbyist does not feel this itch, hence can't scratch it. You need someone with good understanding of the printing industry, maybe access to professional printing hardware. Hard to do on hobby time or as a lone programmer. This is an example of a whole class of problems where OSS tends to do worse than the industry average.
BTW, it pains me to say this as a regular user, krita is very good software.
Well... We think it just isn't that critical a feature, given that Krita and Scribus work together quite well. Especially in this day and age when the the vast majority of images get uploaded to pixiv, twitter, artstation, deviantart and the like. Compared to people asking for help with that, because they don't know how files work, the number of people who ask for a printing feature is minuscule.
I'm assuming you're a Krita developer, so I'll start with saying thank you. It is harsh of me to critique a gift I received for free and you created in your spare time.
But I happen to have a personal stake in this discussion. I'll cite my post from 3 days before this about a little project I was doing:
I took screenshots [...] cleaned them up with krita.
next part of that sentence should have been '.. and tried to print them, then thought WTF??? and printed via some other program.
About every parent at our school prints a lot of little things for the kids, to color or play.
As computer nerd I get questions about good program for X, and recommend e.g. paint.net, photopea, gimp, ... For my public, not printing seems a blocker.
So if you get these requests once every 2-3 years, some part of your potential audience seems missing.
So I think this touches a core problem of open source: The average hobbyist does not feel this itch, hence can't scratch it. You need someone with good understanding of the printing industry, maybe access to professional printing hardware. Hard to do on hobby time or as a lone programmer. This is an example of a whole class of problems where OSS tends to do worse than the industry average.
BTW, it pains me to say this as a regular user, krita is very good software.