Funny thing, but they both failed because they were too powerful, with factory loads, for the intended user (law enforcement).
The 10mm got downloaded to the 40 S&W. The 41 Magnum never got the 41 Special, or reduced factory loads, that LE wanted.
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I think that the 40 S&W is proof of your statement for the 10mm, but I honestly don't think power was the real, final issue with 41 Magnum. 10mm/40 S&W is of different enough caliber to make a difference between its to largest competitors, .35 and .45, to justify the choice of caliber because it will have different enough properties. After 10mm did indeed fail commercially, it did bring about a child cartridge that has seen success, even if it too may be on the wane at some point. 41 Magnum could have easily seen 41 Special brought about, just trim the case.
I think the final nail in the 41 coffin was the fact that its closest bigger competitor was only .429, and 41 is a .41 . While 40 S&W is different enough from 45 ACP to make claims at its average power across the board, 41 Magnum's close caliber to the 44 meant its gains were very small, almost theoretical, and all the of advantages of the caliber lie in high power, magnum loads. The entire theory of its being and supposed combat superiority, even as a hunting revolver, lie in its supposed advantages at high power high velocity over the 44 MAGNUM, if we really want to get serious and honest there is nothing the 41 Special would have offered us that would have been any better than 44 Special.
If you are going to choose a high power magnum for service duty, choosing a smaller one makes sense to reduce recoil and maximize barrier penetration. But, if you are going low power the case for the big bore is far stronger. Thus the Magnum lover might choose the 357 over the 44 AND the 41 for recoil control, but also the Special shooter might choose the 44 over the 38 AND the 41 because if you are going to go big, you might as well go full bore. 38 held its own for people who liked to shoot light and cheap, 357 Magnum held its own by those who liked magnums but not too much magnum, 44 Special held its own by lower power big bore shooters. The 41 Magnum could not displace the 357 Magnum, nor could the 41 Special ever displace or offer advantage over, the 44 Special. It was doomed from day one wither they offered lower power ammunition or not.
If we forced competent men in a hypothetical situation to go back to service revolvers for regular duty, i would guess most would choose 8 shot N frame 357 Magnums, or 7 shot L frame, and if we asked the 6 shot big bore boys what they want some might still take the 44 Magnum. But, for those low power big bore shooters you would get probable answers for 45 ACP revolver, even maybe Model 25's in 45 Colt, and 44 Special. I think by the end of the theory you would not find hardly one who would seek out a 41 Special if it was introduced and offered to them.
