ANY cuisine that one is not familiar with is difficult to cook because you're not familiar with the entire flavor profiles of that particular cuisine. For myself, any type of Asian cuisine, Mediterranean cuisine, French cuisine, and most Latin cuisines (excluding the Carribbean) are fairly easy for me to make because that's what I like to eat and what I'm familiar with cooking. I struggle with other types of European cuisine (English, German, Polish, etc.) and some regional American cuisine because that's not what I grew up eating and I'm not familiar with the entire flavor spectrum of those particular cuisines. Because of that, I don't have the palate for all of the flavors that are used which not only makes it difficult to know what the dish is supposed to taste like, but also in fixing the flavors of a dish and ad-libbing dishes in those types of cuisines.
For anyone to say that a particular cuisine is not difficult to prepare, they need to be able to prepare a wide variety of regional dishes from that cuisine, not just a handful of dishes or dishes that they know in their particular region. For instance, for someone to say that Chinese food for them is easy to cook, they need to know how to cook Mandarin, Cantonese, Sichuan, etc. For someone to say that Italian cuisine is easy to cook, they need to know how to cook dishes from all over Italy: Roman dishes, Sicilian dishes, Tuscan dishes, etc.