I'm not expecting this to actually happen... but I would instantly buy a Mac laptop that let me physically separate the screen and the keyboard while continuing to use them both. Then I could set the screen up on a portable stand at approximately the right height and distance while the keyboard lived closer to me and lower down, perhaps even in my lap.
Right now the best I can do is to carry an external keyboard. But it's a pain to have to tote around redundant hardware. Of course, it's also a pain to be in pain after spending too much time using an un-ergonomic laptop.
The main limiting thing there for me that's annoying is that Mac OS seems to require me to use my laptop's screen as the main one putting the menubar there instead of on my larger external monitor.
You know abhout this "drag and drop" thing? Open up the Displays preference pane. You see the two (or more) screens and you can drag them around to decicde how to arrange your virtual desktop.
Now drag the menu bar to whichever screen you like. And remember, Google is your friend.
In your defense, a lot of "elegant" GUI designs are like this: they lack affordances, so you have no idea that they can be manipulated. But once you learn them, they seem to make sense.
The common alternative, some sort of configuration wizard with 1,000 controls, seems worse. But only just.
In some cases it's just a little more thought -- like here if, for instance, the border of the menubar was highlighted as the mouse rolled over it, it would be pretty obvious, in my opinion.
I haven't tried this, but someone says that if you go into the Spaces view--the one where you can drag windows between all four of your spaces--you can drag the menu bar in there as well!