I don't have any issues with Chinese sellers. It all comes to selecting a decent vendor, making sure expectations are met, clear commincations.
It all comes to do some research. Nowadays, it seems people just see a low price and order. Preferably on Aliexpress, where anyone can sell anything. Knowledge is not required, just grab stuff at a local market and ship. You can put dolls, lifepo4 cells, balloons and pencils in your shop and you have a business.
If you don't do any research, have any suspicion if a seller just has started, has strange shop names, doesn't communicate anything but 'yes dear friend', sells cells which simple doesn't exist (420Ah), sells 300Ah battery packs with a weight of 5kg...
I agree those sellers should be banned, but I also think the buyer is to blame also for not doing any research. It's not only for Chinese. If people are stupid to buy anything without any check but price.. Im sure there are sellers on Ebay/Gumtree/Craigslist also which prefer the easy money. It's not only a Chinese issue.