As I mentioned over in the immersion thread, one of my favorite things, no matter what style of game I'm playing, is exploring the world. If a DM creates a world that I have not experienced before, sincere interest is my way of both respecting and showing gratitude for the gift they've spent time crafting for me. Even if they made it for themselves initially, they're still sharing their passion with me. I get excited when I feel the need to ask a question that's not necessary for gameplay, but I'm too curious to ignore, and joy when I see their face light up with surprise and eagerness to share more.
Maybe some players don't remotely care. Maybe some players care a lot. Most are probably scattered between those two poles. Can we point to anything that shows prioritizing one of these groups is worth the expense of the other? I don't think we can, at least not to the degree where there can be any sort of general advice whether caring about the details of a homebrew setting is "worth" it or not.