Actually, that single-shot palm pistol is the penultimate ergonomic design. The ultimate ergonomic design would be a repeater or even a self-loader that utilized a bore axis that low. The palm pistol was an anomaly of sorts in small arms design and development, but there are numerous weapons that have successfully utilized the low bore axis design. Two of the most famous designs are, of course, the MG34:
and the MG42:
The MG34 was very time-consuming and labor-intensive design, but it was definitely a successful design. And there is no arguing that the MG42 was a wholly successful design. It's still used today as the MG3.
The Germans also employed the low bore axis on rifles. The innovative FG42 used the bore axis bissecting the buttstock:
The FG42 was never widely produced, that is true. But that is not to say the design was flawed. SIG's StG57, for example, copied the method of operation from the StG45(M) and the layout of the FG42:
The StG57 doesn't employ the true "fishtail" buttstock design of the MG34, MG42, and FG42, but it does employ the low bore-axis principle and straight-line layout of these earlier weapons. So do other modern weapons like the M16.
These low-axis designs are by no means a thing of the past. Beretta's new UGB25 is a low-recoil design and it uses the low bore axis:
Krieghoff also uses the low bore axis design on its Trap Unsingle K-80 to minimize muzzle flip and attenuate felt recoil:
On measuring the bore axis on pistols, I think the more correct way to measure the bore axis is not from the trigger to bore axis, but rather from the top of the web of the hand to the bore axis. I believe this latter method is a truer measure of how much the bore axis sits above the shooting hand.
Yes, the 226 is only a 9mm. This is true. But why make the bore line higher than necessary? Why not lower the bore axis to the lowest practicable point? The Glock employs an identical method of operation to that found on the 226, yet it has a substantially lower bore line. Gaston Glock thoughtfully lowered the bore axis on his design as much as he could, just as HK lowered the bore axis on the P7 as much as it could. And they're not alone. One sees this all the time, even on weapons with negligible recoil. For example, take the Hammerli 280 and 208:
The 208 was hardly a hard-kicking pistol but Hammerli lowered the bore line as much as it could and still have clearance for the reciprocating slide. Hammerli lowered the bore line even more on the newer 280, just because it could with the 280's different slide location.
Yes, the 1911 is a great pistol. It has many faults, but no other weapon combines as many great attributes in a single weapon as does the 1911. The 1911 is a SA design, so it is very easy to shoot quickly and accurately. This alone puts the 1911 ahead of weapons like the Beretta 92 and SIG P226. The 1911 is a powerful weapon. This puts it ahead of weapons like the Hi-Power, P7, and Glock. The 1911 is a very slim weapon and is easy to handle and carry. This puts it ahead of weapons like the 226, Beretta 92, and the other M9 candidates. The 1911 has an ergonomic safety location. This puts it ahead of designs like the Luger, Beretta 92, P38, SIG 210, and so on. The 1911 isn't flawless or anything, but it combines the key attributes of power, controllability, and manageble size into a single weapon better than any other pistol design. That is not to say that the 1911 cannot easily be surpassed. It can. For example, a P7 chambered in .45 ACP would be superb. But the gun companies have yet to bring out a pistol that does as much as the 1911 does. It's not what people want. People want high magazine capacity and double-action triggers all sorts of things that destroy controllability.
Your brother-in-law may claim to be a 1911 devotee, but if he owns a Gold Cup, Para-Ordnance, and so on, he's not.
I agree that a Hi-Power in .45 ACP would be very sweet. The Hi-Power eliminates several key weaknesses and complications in the 1911 design and has a better butt profile as well. Eliminate the magazine disconnector, chamber it in a round like .45 ACP or .45 GAP, give it a single-stack magazine, put the magazine release on the right side of the handle, make the safety operate smoothly, fit some nice sights, sculpt the stocks into an ergonomic shape, and you have a superb pistol. This could easily be done. But I'm not holding my breath for Browning to come out with such a pistol. It wouldn't even sell and Browning knows it.