Completely agree with you. The mainlanders are rude, arrogant, incredibly self-entitled, crass and noisy, especially in a group. If you have the misfortune of bumping into a group of them, you'd feel like you just entered a chicken coop, with all the birds cackling at the same time. Imagine that noise. Now turn the volume up to 11.
They also have complete disregard for others' personal space. I have told them off on many occassions. Of course I do it politely, but heaven knows I secretly wish to give them a proper smack on the head. Just the other day, while I was reading some labels on the supermarket shelf, this mainland couple rocked up, stood literally next to me, and the guy extended his arm right ACROSS MY FACE to get a bottle of juice, like I was invisible. Most people would at least say 'excuse me' or something to that effect but no, this ape thought he owned the supermarket.
Last month, while at a waiting lounge in DMK, I was having my pre-flight beer in a quiet corner and a few seats from me was a man who was on his laptop and earbuds, and sounded like he was on a concall or something. Then this group of old mainland birds rocked up and, instead of picking an area away from us, they literally descended upon us, and then started cackling loudly. I immediately moved away. For the record, the lounge at that time was quite literally empty, so I was really, really flabbergasted why they did what they did. They were so loud, the staff from the kiosk had to come out to tell them to pipe down. Five minutes later, that poor man who was minding his own business got up and went to another corner to do his stuff.
These mainlanders are easy to spot. The younger ones will be dressed in bright clothes plastered with brand-name from head to toe - like they were afraid you won't know they're wearing branded stuffs. Basically the epitome of poor form, taste and class. The older generation - like the ones at the airport - would look like they just came out of the village. Only thing missing is a basket full of fresh produce and a live chicken. I'm stereotyping I know, and I don't care. Of all the rude people I have come across (including Russians), the mainlanders are by far the worst I've experienced.