This is a caliber that is really hard to justify in my mind since anything it can do the 44 can do 15% better.
OK... you are forcing me to post!
1) True enough, most .41 Magnums are chambered in guns that are also available in .44 Magnum. But many .44 Magnums could also be bought in .45 Colt and then loaded to above .44 Magnum levels. Some of those guns could even be bought in .454 and you could get even hotter loads. At some point, you have to ask "how much is enough" or at least "how much is more than I need or want to tolerate most of the time?" For instance you can enjoy shooting a four inch S&W M29. But that gun with full power .44 Magnums can really start to wear on your hands and wrists and elbows over time. (Ask my permanently aching right elbow.) Change that chambering and have the same gun in .41 Magnum, the M57. The gun will actually be a hair heavier since the holes are a bit smaller, more steel. And the rounds will recoil a bit less. In most cases, doing 100% of what you need done. If you gradually become one of the old guys who prefers something like a hard cast bullet at 1000-1200 fps, the only advantage of using the .44 Magnum is a piddling little bit of bullet diameter. .410 versus .429.
This might even be more true in a NM Ruger Blackhawk. The 4 5/8ths Blackhawk in .41 Magnum is a decent gun. A little bigger and heavier than I would prefer but it handles the cartridge well. Take that same gun and chamber it in .44 Magnum and you quickly realize why Bill created the Super Blackhawk for .44 Magnum. The standard Blackhawk with a short barrel quickly becomes a ".44 Special level" type of gun in my hands.
2) .41 Magnum suffers from the "no Special" issue. If you want to complain about how the original introduction "went wrong," this is the number one place to start. Remington and S&W should have introduced both a .41 Special and a .41 Magnum. Then loaded the .41 Special as the Police load. Even made some slightly smaller and lighter guns purely as .41 Specials. (This is pre-L frame but that size would be perfect for a .41 Special duty gun.) If guys wanted to buy the Magnums for flexibility but normally carry the Specials, that would work. (Same thing many did with .357 Magnum.)
3) You can get a custom gun today made for the wildcat .41 Special. I actually love OM Rugers in .357 Magnum size that have been converted to .44 Special. I have several. I always wanted to get one of the small Blackhawks converted to .41 Special but price and time kept driving me away. I still have an unconverted .357 OM in the safe that I tucked away for just such a project. But just a few months ago, a used OM Ruger came up for sale on the Ruger Forums. It was a custom gun by John Gallagher. Instead of going with .41 Special, he went all the way to .41 Magnum. .44 Magnum would have taken away too much steel... .44 Special would work, obviously. It had real ivory grips... I couldn't turn it down. I plan to shoot hard cast .41 Specials out of it but the capability is there for more. So, just like .44 Special, one of the advantages is that a smaller and lighter gun can be used compared to the larger cartridges.
Gregg