Hiding menu items is bad UX?

We have soft reject for this reason:

Hiding menu items is bad UX. All menu items should be displaying.

Is this true?

Look at the Amazon Web Services (AWS) on the different resolutions. It hides top level extra menu items that did not fit at the screen size in the last seen ‘More’ menu item.

Is this really bad user experience?
Would it be better to show menu items that did not fit to the screen on a new line???

This is template and who knows how many menu items customer will add?
How do you handle an extra menu items?