The average age of a PhD student is 33 years and even at normal speed, no breaks/hurdles and starting right out of high-school, you are 25(?). Something about applying this babysitting attitude of "somebody needs to tell them" to highly educated individuals of that age just doesn't sit right with me.

If I were a PhD supervisor, I would probably find it ridiculous that one of my responsibilities would be "pointing people to the universities careers service". I'm also not sure why you would expect a supervisor to be able to give good career advice when some of them have only ever experienced academia themselves.