Shouting/cheering at opponents errors

indeed. look back in the old videos from 80’s and early 90’s, players are very unemotional in general. there are no shouting, cheering themselves, nor all the “Chinese shreaking”. they all dress in white, walks in, play, win/loss, shake hands, and leave.

audience are also the same, except in a few countries where the crowd was known for their volume, many countries have fairly quiet audiences. esp so in likes of Japan and AE. where we can hear pin drop in the middle of a match. and audience claps on points and esp for good rallies, with the occasional over-enthusiastic supporters tearing through the silence.

but in the early 2000, things changed. perhaps with some influence in other sports where cheering and grunting are the norm, badminton players started doing the same. even though rules limits the amount and direction in which emotions are expressed, the players are showing a lot more self-congratulatory expressions over the years. with today where rally won are cheered loudly.

and amateur club players as well as local tournament audiences are influenced by what they see on TV. with more liberty on what can be expressed without overseeing umpires and officials, there are even more chances of players going over the rules, without bad intentions. bantering, trash talking are common and i have seen a lot more shouting in local tournaments too.

however, some people are sensitive over what their opponent say/do, and in the heat of competition, it can magnify.

as for the OP’s description, i don’t think he has done anything wrong when it comes to cheering himself. he made an attempt to only cheer for his own wins and also not directed at the opponent.

as for the opponent’s teammates, there is really nothing you can complain or do about. you are playing against the players on the other side of the net.