I know that historically window management on OSX was pretty spartan. Its gotten a lot better in recent versions, so maybe they where used to an old version of OSX and has not tested it recently?
But yeah some of the points about Apple still stand. I don’t think their UI is that bad. Its not the best to be sure but its not horrible, and app performance seems ok?
The other important thing that macOS has going for it is that once all my none techy relatives had Macs I no longer get IT support calls from them. Admittedly they moved from Windows to macOS.