FreeDOS gets used in several pre-built computers. HP is one example - HP EliteBook comes with a FreeDOS option. And Dell used to do this, don't know if they still do. There are a bunch of vendors (especially in Europe and Asia) that pre-install FreeDOS, too.
Alas, these pre-built computers have FreeDOS on them mainly as a clever way to get around a licensing agreement with Microsoft. I understand that Microsoft put a term in their Windows OEM license that prohibits system builders from selling "naked" computers - systems without operating systems. If you want to get the huge discount on Windows OEM licenses, so you can sell pre-built computers with Windows already installed, you may not also sell these "naked" computers.
But there are plenty of people out there who don't want an operating system pre-installed (I presume these people are like me who prefer free software, and who would install a Linux distribution on their new computer) so system builders started shipping computers with FreeDOS pre-installed. I think the premise is that customers will reformat the drive and install Linux anyway, but the system builder didn't technically sell a "naked" computer.
I actually think this is very clever and I like the idea. A few users do keep FreeDOS installed on their system; occasionally I get emails from people who decided to keep FreeDOS installed (and probably dual-boot into Linux) so they could use FreeDOS to play old DOS games.