At the very least compare citing to "assist" in soccer (or another sport): record is kept (statistics) and rewards follow (recognition, remuneration..)
Try thinking about it also in terms of fairness and replicability.
This short video goes a little more in-depth on why citing is important:
Additional guides with examples.
A reminder: CSM library databases contain citations to all the articles available there...just look for the "cite" or "email" on the search results pages!