James Gasik
We don't talk about Pun-Pun
Woah there, this isn't me personally doing this. It's just how I've seen backgrounds occur. DM's will forget they exist and be surprised when they come up.Why? You literally tailor-made everything for their backgrounds to count! Why nerf it?
If it really bugs you, just remember that you said everything is available for a price. The nobles will only grant an audience to people who give them impressive gifts. The librarians make a pointed glance at the donation box each time the player asks a question or wants to see a book, or a membership fee in order to get into the restricted section. The ship will take them after they make some repairs, but that takes time since they don't have the gold to expedite those repairs, hint hint.
Or just have a completely unrelated adventure ready for times just like this. One sorcerer sending assassins after another one (and the one they're being sent to also happens to be the one the PC is going to), monsters wandering the streets at night, a sorcerer testing out an illicit spell on the unwitting populace, something like that.
It's not what should be happening with backgrounds, but it's what I've seen happen in actual play. Ideally, the DM should always be aware of the backgrounds the players have and try to work them into the game so they are relevant more often, but that can be extra work, and adventuring doesn't always let things like being a sailor be relevant as a matter of course.
In many games, it just happens that the DM might just legitimately forget. The players too. And then it can be a surprise when it does come up, and well, most DM's I've encountered don't always react well to surprises. It's a thing.
I have a Wizard who knows Mending as part of their backstory. Mending isn't a very useful cantrip. When it actually came up in a session, the DM was like "let me read that", and then ruled that Mending was useless in the situation (which to be fair, it's a pretty limited cantrip).
I have seen Backgrounds end up just that way- the little used, oft-forgotten ability that the DM could have planned for, but didn't, and so when it came up, it's a nothingburger.
I don't see that as bad DMing, it's just the reality of the situation that some abilities are just too niche for the game to always support unless the DM goes out of their way to make the magic happen, and they got a lot of other stuff to worry about, especially in a game where combat, something Backgrounds aren't usually relevant for, is such a large part of the game.