I agree with wesza that the availability of fresh and top-quality ingredients in Hong Kong in the past few decades, under its special circumstances, has a major contribution to making Cantonese cuisine so successful.
If you brought together people from each province in China and asked them what they thought the best Chinese food is, I am sure that in every case they would answer with their province (or their "region").
This seems to agree with what I said earlier about if I grew up in the Carribeans eating nothing but bananas, I may think the food from the rest of the world is no good and only bananas taste the best.
Cantonese cuisine uses ingredients that are typically more expensive and "higher class" and thus there is a propensity of high-end Cantonese restaurants in China. I think this is part of the issue, I couldn't imagine many people going to a high end Sichuan (or for that matter Xinjiang) restaurant, because this is everyday food, it can be found everywhere and is good whether spending 5, 50, or 500 RMB.
I don’t think this is true at all, what you said about Cantonese cuisine uses ingredients that are typically more expensive. You may be referring to those dishes found in Chinese banquets. If you walk in to a restaurant in Hong Kong, or here in the USA or Canada, you can find plenty of dishes similar to what you called “everyday food”, such as beef stir-fried with vegetables, beef stew in hot pots, chicken with black bean sauce, Hong Shao Do Fu, roast duck and barbequed pork, etc.. These ingredients are not considered expensive nor “higher class”.
However, too often (from my experiences) Cantonese food, at least in cities outside of Guangzhou/HK is only good when you go to the higher end restaurants.
I think the issue is, at least partially, when you and other fellow posters slammed on and said “Cantonese food is bland”, “all show and no taste”, you may be basing your broad judgment on a few limited Cantonese “bland chop suey” restaurants in the U.S., or a few what you considered as “high end” Cantonese “all show and no taste” restaurants in China, or the cooking done by a Cantonese friend. If you have the opportunity to spend some length of time living in Hong Kong and don’t be afraid to try the local Cantonese food, you may open up your mind a little.
I think Gary Soup would agree with me… take San Francisco for example, there are plenty of restaurants in or outside of SF China Town which offer excellent common “everyday Cantonese food” for less than US $5.00 a dish. They are good (in fact excellent) but nobody would consider them as “high end”. Have you ever tried dining in those places? Have you dined in Cantonese restaurants serving “everyday food” in Portland, Seattle, Monterey Park, San Jose, Los Angeles, Cerritos, Irvine, New York City, Boston, D.C., Philadelphia, Toronto, Vancouver, Montreal? These cities, all outside of Guangzhou/HK, have fairly decent “low end” Cantonese restaurants. Yes, my personal experience.