I dunno. Maybe because I-O-M is the most relentlessly user-hostile GUI program in the history of computing? Raw data manipulation without a metaphor thrown over it?
Back in the BeOS days, third-party sets of bitmap icons were posted up at a rate of one a week. I've rescued about a hundred and put them in my repo. Since the HVIF switch we've had the McClintock set and the BeBeautified set and ... well, that's it. really. Makes you wonder why that is. Surely making icons is an easy way for newbies to contribute to the project?
Search the forum. People will import SVGs, they will design in Wonderbrush and import from there, they will use autotrace - ANYTHING to avoid designing in I-O-M. Or they will just ship apps without icons.
About a year ago someone (might even have been you, I forget) sent me a tutorial. And no matter how faithfully I followed the steps, nothing ever appeared in the drawing area. Thanks for trying, anyway. This is the single part of haiku that I really hate. It should not be allowed within a mile of a newbie, because it might put them off Haiku forever.
If you can make this thing perform, let us know your rates. You might be the first person to actually make money out of Haiku.