Why would password authentication be more secure than token authentication for a Jupyter notebook?

Question

I have an account on a remote compute node, and would like to be able to launch a Jupyter server and share it with an intern, who does not have an account on this particular server. The natural method to solve this problem seems to be the accepted answer to this question.

In the comments, it's noted and acknowledged that without setting a password, this method is insecure. By default, Jupyter generates a token by default, and you can't access the server without the token. Why is that method less secure than setting a password?