What there's locals that have an overly simplistic (and generally wrong) perception that generalizes a given aspect of western life, and they stubbornly remain set in their ways and refuse to believe your lying words?.... I find that hard to believe.

It's because that's the only wetsern food that most of them will ever eat or see here.  Crappy pizza and burgers.
Or at those "coffee" restaurants where they do serve a wide variety of western food but only the rich can afford to eat there and the food all still sucks.

I'll back Crimochina up a bit here. One of my colleagues asked in all seriousness if all we eat when back home are sandwiches; her English teacher at college had told her this as a truism and it stuck!

Don't forget chips and sandwiches!

The most popular Western restaurants in China are KFC, McDonald's and Pizza Hut so that's all they know about. That and willful ignorance. 

If my only exposure to western food was the "western" dishes offered here in China, I'd say it sucks too.

For the same reason people back home think Japanese food is sushi.

I have to say, their "burgers" are the worst burgers I have ever eaten, and I don't mean from McDonald's because I won't touch those. I showed my classes a bunch of real American food for a class, so I hope they understand there is a large variety of American cuisine, and not just fast food. I'm pretty sure that before that, they all thought we eat fast food all the time. The few people I've told were shocked when I said my family doesn't eat fast food at all. I've eaten more fast food in China than I did back home, and I've only gone 3-4 times in 5 months.

When I am invited out for dinner here and I am asked if I want to eat Western food I quickly say,"No thanks."
Then they may ask,"But don't you miss your home?" I would have to miss home a lot more to subject myself to the crap they disquise as Western food here. I chaulk it up to plain ignorance.

I can hear it now, the chef says..."I can make a pizza, where's the mayo and potatoes?"

I know what you mean! I have often mentioned how much I miss good Italian food and some react telling me that pizza is unhealthy and that they dont like spagetti (Idali-mian). Once I even described the different kinds of meat that the Italians have and the guy I was talking to said "I dont think so"

I found they like steak, but the western food here mostly sucks. I never had a good salad, had the saddest pizza ever in a Russian place in Yangshou. Njord had told me to wait and get pizza there.
 Even at home the Chinese women I know think our food is so simple, but they can't cook. The China women I know can't cook either. Must be a global thing because most of my Canadian GFs couldn't cook. Yuummm,  I always say carbon is a major food group.
 My favourite western food is to go out for Chinese, always has been.

By believeing that everything outside of the Middle Kingdom is plain and simple, it allows nationalists to rest safe in the assumption that their culture is the only one varied and old enough to be deemed interesting.

To do other wise would take inititive and curiosity; exploring the nuances of blended cultures, and coming to the realization that variety is what makes things exciting, and not sameness.