Not who you asked, but there is something amusing about fiddling with a physical system, plus you can keep it on regardless of your main computer, and doesn't take up a window/tty/otherwise clutter the host.

Maybe, but try to get into the mind of someone who installs a minimalist OS. They might think that Linux is too heavy and an RTOS is too constrained, right?

That kind of perspective probably wants to be fairly close to the metal, and virtualization is a sizable abstraction layer.

Yes, unless you want to play with peripherals too.

Like another commenter said, being able to put it on a shelf is nice. You can crack it open 5 years down the line to play with, or just give it to a friend that's interested in trying different OS's