Agreed. In my class I always start with the hard/wrong way. Point out why it's hard/wrong. Let them hate it. Then show the easy/correct way. You can't just point them at something and say, "Do it this way or else." That's not teaching. That's directing.

I feel like you could start with manually calling the function, and then introduce callbacks as a way to get your code to run in response to some event. A callback is no different to a regular function after all.

If your way works, then it works though I suppose.