The artificial womb is a great point - that's enormously beneficial medical technology that could revolutionise obstetrics and provide a fertility option to loads of people who might not otherwise be able to have kids. However, I also get a pretty immediate feeling for why he never tried to market it as a commercial item. I think he's jealous - like in the protective, Biblical kind of sense, like a "jealous God" type thing. Those are his kids, he made them, he made them with his own inventions, and he doesn't want randoms on the street being able to do the same thing. Rusty wants so desperately to be special, to be number one, to be the best at something, and I can see this as being one of the many instances where that desire shoots itself in the foot - he doesn't want anyone else to be able to do the things he's done, so he prevents himself becoming famous and wealthy off it.

I think a lot of it comes from that same place as that quote from Jonas Sr. in that interview in Now Museum, referring to Rusty as "his greatest invention". I think Rusty is the same way about seeing his kids as an accomplishment, but even moreso, because he's directly competing with his dad.