- WTF is arpa? (in reality, I know, but there are better names than an obscure reference to internet prehistory)

- it is a second-level domain, why?

- 9 characters (home.arpa) is a lot

I kind of understand the motivation, it is a "technical" domain since it doesn't represent something in the global DNS registry, so it gets the .arpa TLD. However, that's reasoning that it out of touch from normal users. Normal users don't want to be exposed to the technicalities of DNS when they enter something in the address bar, and "myserver.lan" is more meaningful than "myserver.home.arpa", and giving meaningful names is the whole point of DNS.