The poster seems to assume that just being near content is the same as engaging in it, even if they don't know what to look for. They seem to think rumours aren't hooks. They seem to think that everyone who goes to Waterdeep is equally likely to get involved in political schemes and a treasure hunt.
My suggestion? Tell the players what the hook is. Then, make sure the characters they make fit the hook. If the hook is a mutual friend, make sure they all know the guy. If the hook is a job posting, make sure they're all looking for work.
Bonus points for having multiple hooks. Either you can move players towards the one that fits best, or you can give them options in which hook to focus on.
I like that many (all?) of the Mausritter one pagers have a d6 table of hooks when using it for a one shot. It gives a little randomization to the start and can result in very different stories.
Luke seems to have campaigns in mind where characters bring context and background.
Part of running a table is establishing the dynamic with regard to motivation and scenarios.
Thus, a prefab module doesn't need hooks, but there's nothing wrong with them being used as a starting point. You don't have to slavishly follow modules to begin with. It's just another part of the kit being provided. Use it or not, as fits your table.
Why would I care about the Goblin attacking a remote village, or the kids vanishing from a summer camp ? I have a job to do, don't want to die. Why would I cooperate with person I didn't know a before the game start ? Sure, it's a game, and we all want to play, but when both the player and the GM have to make a lot of compromise to make the scenario playable, it just breaks immersion.
However, where OP is right, is that very often, the plot hook cannot be written by the scenario author, and when they do, it feels artificial (So you were arrested by the cops and are offered a deal to get out , or you dream about a mysterious jail which is now a mental hospital) a GM crafting plot hook based on the PC backstory and the discussion in session zero. Another big question to ask : Why do the PC want to work together ? There is tons of horror stories about our families have been hating each other for generations, I don't trust you which can make campaign complicated, hence things like Camarilla archonts in Vampire or Emerald magistrates in L5R, or even Delta green for call of Chtulhu it gives both plot hook (it's your job to investigate) and reason to cooperate it's your fucking job
As I interpret it, the purpose of a hook is a big signpost to your players that says “hey the prepared adventure content is over thataway”
If they are down for the social contract they will presumably not be dickholes and interact with it. Of course, it is your job to make it engaging and give them a reason or shut all the alternate pathways off or however you want to do it. But likewise it is kind of their job to interact with the clearly marked “adventure is here” signpost as opposed to implicitly saying “naw fuck what you had prepared I think we would prefer you had to wing it, it’s what my character would do.” Ttrpg environments carry a significant implied social contract on all sides.