You're not addressing this point: Why did nobody even try to bring one to market? Enough other really bizarre, ungainly, and ultimately unsuccessful guns have been manufactured (COP, anyone? Gyrojet? Dardick?) that just handwaving it off as "they wouldn't sell, so nobody even tried" isn't really convincing to me...especially when you have Seecamp trying to make the smallest DA auto he can in the most effective cartridges that will work in a blowback gun and those being in such demand that just owning one was something of an accomplishment.
No, I'm not missing the point at all.
Like so many other aspects of life, this is a holistic event. More than one thing conspired together to make things the way they were with revolvers and pistols.
Nobody bothered trying to make any headway into small semi-automatics beyond the calibers you mentioned because there wasn't a market for them.
The firearms market is a tough one, it is and it was in the days of yesteryear. There has to be a sustainable demand somewhere if you want a particular design to succeed...not only that, but it will be in direct competition with whatever is already established on the market.
The civilian market didn't really start picking up on semi-automatic pistols until AFTER various government agencies started migrating towards them. And when they did, the civilian market not only picked up on semi-automatic pistols, they picked up on the calibers that were popular with those various government agencies.
And those calibers were pretty much .45 ACP and 9mm.
Once the market opened up with civilians, then you started seeing more people making and marketing semi-automatics that the public wanted...and in the beginning, what they wanted was what the government agencies had, which was mostly .45 ACP and 9mm.
Over time, the market gained a lot more diversification and more and more options were opened up to the public. In the 40 years since the majority of government agencies started switching to automatics, there has been a huge explosion of diversification in available calibers, designs, and sizes.