The author pretty clearly states why they used the form factor:
it’s my take on the slab style computers that were somewhat popular before the world settled on clamshell designs for portable computers. I really wanted a TRS-80 model 100 when I was young so this sort of design was a big influence.
not everything is built for everyone, and that’s cool & fun
i’ve been using arch as my daily driver for 4 years. but i am thinking of switching to chimera linux. i really like apk, i think using dinit, llvm, musl and *bsd core utils would be great. for server, i use proxmox as my hypervisor, and debian for most vm’s, starting to use alpine on lxc. I am using openwrt on my router.