Preferring a partner taller or shorter is not shallow, however demanding they need to be shorter than a certain height or taller than a certain height is shallow.

Saying I prefer to date someone taller than myself is a preference, as I am okay with dating someone shorter than myself too. Saying I would not date someone shorter than me, and I will only date someone taller than me is not a preference, it is a physical requirement, therefore it is shallow.

If a 5'4" guy gets married to a 5' woman for example and claims he would never date a woman taller than himself, it is shallow. If a 6'2" woman gets married to a 6'5" man and claims she would never date a man shorter than herself, it is shallow. Because they never would have dated their partner or even been married if they weren't as tall or as short as they were. They may not care if their partner randomly became taller or shorter one day but their height was definitely their first love, not the person.

So there is also always a possibility they love the person for their height and not who they really are, because they have shallow height requirements and not preference.

CMV