People here avoid sitting near everyone. If you have 5 bags of stuff(cause that what tourists do), or even if you are overweight (something not that common here, and space-wise is a wise decision) then even worse.
But I don't think you are trying to have a conversation here, than just trying to push "facts" you read on reddit.
Not overweight and no bags at all. And it's one thing if they were already sitting and then get up if you sit next to them, but were fine sitting next to other Japanese. They are not exactly subtle about it.
I'm not trying to push anything, just recounting my own experiences.
But I don't think you are trying to have a conversation here, than just trying to push "facts" you read on reddit.