Theism has never provided answers to these questions, only curiosity-stoppers.

You can only see this because you are not confused. All wrong answers act as curiosity stoppers to a degree, but you can accuse an answer of ruining curiosity only to the extent you know that it's accepted more than it deserves. Every mistake is inherently wrong, but not every mistake is apparent.

The question "Where did people come from?" is one that you'd expect to be answerable, and therefore a reasonable question to ask. We might, in principle, be able to do research in the physical world to figure out where we came from, since physical events (such as the appearance of a new species) leave traces in the physical world that we might be able to detect long after the fact. Likewise, intuition suggests that everything in the physical world comes from somewhere, and so an answer of "We were always here" seems intuitively unlikely.

On the other hand, if you ask "Where did God come from?", you're talking about an entity that (in the case of a Jewish-style God) predated all physical existence. There's no reason to expect us to be able to figure out where God came from, if a God exists. And since God doesn't have to play by the rules of the physical world, "God always existed" sounds much more palatable than "humans always existed": God isn't something we expect to obey our intuition. God is supposed to be inherently perfect and unchanging, so "God always existed" fits in nicely with our picture of God.

Now, you can fairly say that this is all completely unverifiable and can be matched up to any facts you feel like by altering details. You'd be totally right. But there are real reasons for why many people ask "Where did humans come from?" and don't ask "Where did God come from?" It's not just because they're "not allowed" to ask those questions -- the people who came up with the answers sure were allowed to ask them! It's because the idea of an eternal God is intuitively more satisfactory than the idea of eternal humans, even if this breaks down upon closer inspection.