When Apple began to make a few alterations to the macOS to adopt features from iOS, you can bet that some Mac users howled. So being able to switch the direction of scrolling to the “natural” direction used on iPhones and iPads, and other minor interface alterations, were sharply criticized.
There was a method in Apple’s apparent madness, and it wasn’t to kill the Mac. It was more about making it possible for you to do some things the same way on the two platforms. But the Mac remained the Mac and iOS gear remained separate, even though the operating systems are all descended from the same source.
For some, it was expected that the macOS was surely on the way out, and you’d soon run iOS on Macs. But using a mouse or a trackpad with a physical keyboard are different than working exclusively on a touchscreen. Obviously the end results must be essentially the same, and so Apple had to adapt the systems to conform.