The author's previous iteration of a library for multi-user text editing was called libobby, so that it'd be manually linked with -lobby. It might have been named some time after reading about libiberty and the like. Naturally, the Gtk GUI app had to have a G prepended to that, and the name was kept even though libobby was dropped in favor of a new, C-based library implementing a more complete algorithm with a slightly less gimmicky name.
That's the thing with languages. Laura means penis in Hindi (or the tip of it), and it's kind of a proper word, not just a slang. Randi means prostitute, another proper word. These are the names people must have chosen for their children at some point.
So people usually just pick a name that is not a slang or offensive or heavily inappropriate in the languages, cultures known to them.
UK slang, in some regions at least, for someone who talks a lot, perhaps when they ought not, thus usually somewhat in pejoration - "She's a right gobby cow, she is."
I've definitely heard of someone having the "gift of the gab", meaning they speak convincingly (I think I've only heard it used to describe sales people though).
"gift of the gab" can be positive, meaning a confident successful communicator (and sometimes socialiser) though tone of voice can turn it negative, meaning someone who successfully communicates bullshit (got instance in a marketing context).
Gobby is pretty much always negative, meaning loud, never shutting up, often also implying overly opinionated and/or obnoxious.
gobby was/is the testbed editor for the protocol originally called obby (now infinote). As many GNOME based applications of the time, names where usually prefixed with a 'g', hence gobby.
In New Zealand "gobby" is slang for a blow job, not sure if that makes me want to try it more or less though.