I actually don't mind this at all. These days the norm seems to be to drop features just because it's more convenient. I think this hybrid approach is not bad at all: the new menu is more aesthetically pleasing and consistent from a UX perspective, and if you really need something that is not there yet you can always use the old menu.
For all its faults I think it's strange to criticize Microsoft for maintaining backwards compatibility.
Isn’t the real problem that the new menu somehow can’t show the missing entries of the old one but with its new coat of paint? It’s all data, why can one of them not display the old data?
The Windows 11 default context menu uses a newer API (IExplorerCommand) compared the older method which involved screwing around with the registry, and having everything play nice.
Frankly, this just follows all the same problems that MS has had with since after W7. Their own APIs have a lot of warts and problems, but MS has not been able or willing to follow through on the migration required to actually move to a whole new API. This has shown up in their Windows GUI frameworks, it's the exact same problem with the Control Panel vs Settings, and here it is again.
I can sympathize with many of the stated goals/benefits, and I can understand the technical difficulties with transparently porting registry craziness into their new framework, and infact I applaud that their fallback is "perfect" - it is just the old context menu. I just wish there was a setting toggle to set the default.
For all its faults I think it's strange to criticize Microsoft for maintaining backwards compatibility.