So first, it's literally only the PCs that don't have it without a feat, so for balance reasons some very, very, very, very, 1000 more verys, few don't have it. Second, the lore straight up says that they got it from the goddess, not that they believe that they got it from their goddess, so I have proven that in 5e that's where they get it.
Feel free to change it for your game, though.
Not enough to matter.
1) Without a population distribution, you can't say how few.
2) It says they were taught. Not given.
3) Now we have moved from "there aren't enough who don't get it to matter". Funny how that just seems to keep shifting.
Yes, you can homebrew an NPC deep gnome without the innate magic. I don't dispute that. As I said above, feel free to do so. It takes the DM deliberately removing it, though, to keep them from having it. Your homebrew doesn't change anything that I've said.
You realize that the homebrew in this case is to
ADD IT, right? So your statement is completely nonsensical, unless you think that customizing the statblock is the default RAW and using it as written is homebrew. Which, I'm just going to tell you, would never apply to literally any other option in that book, other than to those NPCs to try and prove your point.
It was an absurd thing to say, then. The mental gymnastics involved were mighty.
What, that a god can teach something that can eventually can become innate to the people?
Nope. That isn't absurd or taking any mental gymnastics,
You can't teach innate magic. It's..................innate.
No it doesn't say that Baravar taught them innate magic. It says magic, which is wizardry and the like. Innate magic is...........innate, not taught.
It is by RAW explicitly innate. Look at the Deep Gnome entry in the MM AND the Mordenkainen's lore. This is not disputable in any rational manner.
And so we get back to your imposing your logic on the world. You have decided that it is impossible to teach something that became innate to the race. That isn't something that we are told, and in fact that is something that is often done in mythology.
You have also assumed that Baravar taught them wizard magic, and granted them additional magic above and beyond the magic they are known for. The book doesn't tell us that, that is your assumption. It just says "magic", which is what they have, and so what possible reason could there be to assume he taught them magic, and then gave them entirely separate magic?
We know that not every Deep Gnome has this magic, both from using the NPC statblocks in the back of the MM and from PC builds. So, this innate magic can remain unavailable to the Gnome. Perhaps it is much like sorcery. Sorcerers can be born with innate magic due to living in high magic environments, but must be taught how to use that magic. Perhaps the Deep Gnomes were taught this magic, then simply used it so much and so often, it has become innate to them, but they still must be taught the proper ways to use it. This solution seems to work for everything, them being taught, it being innate, not everyone having it... except then their God taught them. Like I said and like the book said. Which would make me right.
You know, I can think of a great example too, after looking at the Forest Gnome entry on Illuisions. It states: "Forest gnomes have innate magical ability, letting them create simple illusions.
They practice the use of illusion magic from an early age." Know what this made me think of? Cats. Cats have an innate hunting ability, they are natural born hunters. And yet, in the wild, their parents teach them how to hunt.
Gnomes were taught illusion magic by a God. This gave them an innate skill with illusions, one they must practice and teach others. But it started by being taught, and they have to practice and teach to get full use of it, because "innate" doesn't mean "skilled"
You do realize that taking possessions is secondary to the primary objective of wealth, right? It's an opportunity grab, not the goal. The goal of goblins is not to raid for spoons.
And yet you are more likely to find bent spoons, broken pottery, floral drapes and other mundane items than a single gold piece or gem in a goblin lair.
They raid and take "stuff" not specifically "gold and jewels". Which makes a halfling village just as tempting to them as a human town.