I've had a run in with very specific groups of Chinese acting curt and transactional. Why is this?

This is mainland China people I believe, and not Taoists or Falun Gong. I think they're some type of Confuscionist. But I'm just speculating.

These have all been extremely curt and rude interactions. Like they would not even fully acknowledge me. This is not a language barrier thing either as they'll nonverbally or with a one word answer acknowledge and leave if they even recognize me.

All of these people were acting like they were on an extremely tight deadline and no matter if I helped them out or was a neighbor they'd just respond rudely and curt, and inconvenience me by making whatever task we mutually shared take a few minutes to an hour longer for me since they just left after achieving their goal. Even if, my help was necessary for them to finish they would not have the courtesy to spend an extra minute to help me finish.

Whatever they were doing it would have not extended the time to get there by more than a minute. There's a really cold and transactional type of person I've run into from China, and how transactional they are is definitely socially unacceptable in West. I think it is a small group that tends to be extremely financially successful in China. What's the cultural reason for this behavior the West perceives as rude, inconsiderate, and sometimes inconvenient?