Oh, there can be all kinds of uses.

For example, I own an LTO tape drive. Unfortunately, I couldn't get the IBM drivers to compile on my particular flavor of Linux, but I do have a dual boot system.

Now, Windows is a shitty, shitty OS that I only boot up when I really need to. It interferes with all kinds of stuff in ways I hate, for example - copying files. It just refuses to read large files in a continuous, reliable data stream without any interruptions from my SSD when backing them up to tape. This causes the LTO drive to slow down, speed up, rewind, which is not a good thing because it causes additional wear on the tape.

Fix: Create a large RAM drive, copy files to RAM drive, run backup with RAM drive as source.