How did 1/2 orcs get a boost in 2e when they were removed from core?
I don't know for sure, but I suspect its because of the same reason you started seeing more non-Core PCs (like my first Drow, a Rgr/Druid/MU PC) at the end of 1Ed: Dragon Magazine.
Remember, at that time, it was the official in-house company organ. What got published in Dragon was quickly adopted.
You have to stop and ask why though? Why did all those bits get given away to other races? Is there some grand anti-gnome conspiracy, or is it because gnomes were never a popular race?
I always
did ask why.
No, I never suspected any conspiracy. (Not even against the Gnomes of Zurich...)
My guess was that few designers were as familiar with gnomes (esp. the name's interchangability with other terms) as I was. Sometimes they're fey pranksters, sometimes they're elementals, sometimes they're the greatest craftsmen in the world, sometimes just twisted little men...
I suspect that many of them got their main exposure to the term "Gnome" and the like in works of fantasy by modern writers (JRRT, Lieber, etc.), who, recognizing that confusion would result from a single race being called by 5 or 6 names, settled on one, be it "Elf" or "Goblin" or whatever.
With that as a basis, a designer might not be aware that one author's "Elf" derives from the same font as another's "Goblin."
I'm not saying I know more mythology, etc. than the game's designers, just that my exposure was different. Were I designing a FRPG based on the Kalevala based on my single reading of it (esp. without underlying or surrounding cultural context), I'd probably make similar mistakes. Similarly, it was years before I found out about the origins of "Drow."
Not an excuse, just a reason.