This seems like pretty bad advice.
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.