I have to admit, I don't have a favorable opinion when it comes to Chinese tourists. I have more negative experiences with them than positive, mostly along the lines of them failing to observe proper traveling etiquette. The same goes to when I was in Iran, where I saw several instances of Chinese tourists who I must say, could improve when it comes to traveling behavior.
By the way, I don't know why but Iran seems to be popular with Chinese tourists. Heck, there's even a Chinese version of Lonely Planet Iran, and almost all Chinese tourists I bumped into were carrying one. I mostly saw them in the big cities in the central part of the country, namely in Isfahan, Yazd, and Shiraz.
There was one time, when I was in Yazd, and I was booking a day trip to go to small towns and villages outside of Yazd. I already signed up, and was waiting for the group to form, and I overheard the conversation between the Iranian tour operator and the Chinese tourist. She was complaining that the cars in Iran were too old, and so she was asking, no, demanding, that she and her two other friends would be put into a car that was not old. And here I was thinking that the Chinese tourists mistook an old desert city in Iran to be Tokyo. Talk about misplaced expectations.
Second, they also could use a little bit of sensitivity training. Iran requires every female to wear the hijab and cover their hair. Man, the Chinese tourists have very head-scratching methods of implementing that. Some tourists felt like they could get away with wearing a rain coat. That just looked stupid, wearing a plastic or nylon piece of clothing in a desert environment. And there are others who don't care at all, even flaunting the hijab rule. There was this one lady, a dragon shall we say, who from the looks of it was a control freak, as she was pretty much dragging her pathetic husband all over the place. She never once covered her hair. She and her husband stayed in the same guesthouse I stayed in Yazd, and during the time I was there, I always saw her hair uncovered. As much as I do not personally agree to the mandatory hijab requirement, I also do not agree to explicit flaunting of rules of visitors, as I think that is just plain impolite. When you're in my turf, you play by my rules. Period.
The day I did the day trip in Yazd, I was the single non-Chinese tourist in a tour group of 20 people. There were 19 Chinese tourists with me, 19 people who were all obsessed with taking the best photo of the ruined village, the best photo of the fire temple, and the best photo of the windcatcher. They didn't care that there was a tour guide explaining things to them, while trying to keep them all together, as getting lost in the labyrinthine mud villages isn't a great idea. It's as if the tour guide didn't exist, and they only wanted to take a photo and use their selfie stick. Overall, I found them rather impolite, and not good company to deal with.
Of course I am generalizing here. There are also a few exceptions. There was one Chinese girl who I actually bumped into several times in my trip, in several cities. She was traveling alone, unlike most Chinese tourists. We even spent an afternoon together simply because we would otherwise be walking around town on our own. Nevertheless, people like her were the exception.
So yeah, when I have experiences like the ones I have, I can build a probabilistic model and determine that whenever I meet a Chinese tourist, if this person is not alone but in a group, there is a high chance that this person would be impolite. Heck, I just got another data point confirming this, when I was in an aircraft recently. We landed, and we finally could stand up, and there was a Chinese tourist from behind me who almost knocked my head off my neck because he roughly reached in front of me and retrieved several bags from the overhead compartment ahead of me for him and his friends.