I think you can already guess where this comment is coming from! Potato is better known as 薯仔 syu zai in Cantonese. You won't see potatoes on many menus serving Cantonese or food from other provinces in that south/east/southeast coast region.

That's cos sweet potatoes and taro are more commonly used in these cuisines rather than the humble spud. That said the potato is used in in Cantonese home cooking, usually in casserole/hot pot dishes.