I'm not sure if this will help explain the culture or not, but this is from the NTT (the Japanese telecommunications company), so probably they thought that everyone knew what BGP is (since that you probably won't encounter this otherwise).
Searching around, I found someone that benchmarked gobgp, rustybgp, and some others, and gobgp didn't seem to do all that well compared to other implementations.
rustybgp seems to do pretty well (see #5 post of blog series) and is created by the same author(s) of gobgp. Additionally, it looks like the configs are transferable between gobgp and rustybgp.
Also, they have a Rust version: https://github.com/osrg/rustybgp