I agree. But if it's difficult or time-consuming to do so, many people will not. For certain users in certain cases under XP, it can be difficult or time-consuming to do so.
But I'd make the point that so many of these are unnecessary.
Some people are quicker using the mouse to operate the GUI. Others prefer to learn the keyboard shortcuts, where you can really fly without moving your hands from the keyboard. One person may not strictly need several ways of doing something, but it is nice for many people to each be able to choose how they are most efficient at doing it. Considering it costs nothing to have shortcuts for commonly used functions, I don't see how that is a disadvantage. Are you telling me Macs really don't have such shortcuts?
It takes about two minutes to set up a standard user on a Mac. It is not difficult. In an administrator user account click on System Preferences on the Dock. Select Accounts. Click on the "+" at the bottom of the account list. Enter the Account user's name. Give them a password. Decide if they can change their password. Uncheck the "allow user to administer this machine." box. Add a user picture if you want. Exit. Done.
If you want to convert your current account with all its docs and settings tp a standard account, create a new account, make it an administrator, and then uncheck the "allow user to administer this computer" box on your original account. Done. Don't forget the password... it is NOT stored on the computer... if you do, you will not be able to do any administrative functions.
Are you telling me Macs really don't have such shortcuts?
No, the Mac actually has more keyboard shortcuts... and every shortcut is described next to the appropriate menu listing. For the most part, they are consistent throughout all applications. About the only thing to learn is that where Windows uses the ALT key plus another, the Mac may use the Apple Command key plus another (usually the same as Windows). A user can also customize his own shortcut keys or change any of the current ones except those that have been reserved by Apple.
For Windows users here is a list of Windows' keyboard shortcuts.