Just to have a look at the OS. You don't need bare metal to see how it's laid out, built and so forth. No need. As far as this...
Just read a review where the install failed on hardware so the distro was tested in a VM
any number of reasons it could have failed. Is possible that a certain piece of hardware wasn't compatible (not likely but possible). VMs let you look at it without losing anything, and for those of us who don't have multiple computers sitting around gives us a safe way to experiment without wiping out our only working machine.
They are also great for educating yourself. If it wasn't for VirtualBox I probably never would have made the switch to a pure Linux environment for myself. I ran countless virtual machines. They were real enough that I had real experience running, managing, fixing Debian based distros. Also learned a great deal of networking basics, how to run a pfsense box. For not being "Real" they taught me a great deal.