How to minimise your opponent's fun in a game? I play numerous online chess games and in this question I am self-centred: I play for two purposes: 


to win the game, or when winning is unlikely, to draw the game.
to improve my chess skills, which eventually enables me to win/draw more games.


I do not care about my opponents' fun. I do not care if they feel frustrated or bored. However, I will remain polite and I am against bad sportsmanship.

Here is my logic: when my opponent finds a game non-interesting, they will more likely make inferior or aimless moves, or even blunders, and thus increase my chance of winning.

A few thoughts:


When the opponent invites me into a sharp line, decline it. Make moves to solidify my position instead. Decline most gambits.
Choose boring openings whenever possible.
Choose openings that my opponent does not like, if I know their preferences.


Is the idea of destroying your opponent's fun good? Are there any other strategies to bore my opponent so that hopefully they will lose their patience and start making inferior/aimless moves?
I play for two purposes: 
  
  
  to win the game, or when winning is unlikely, to draw the game.
  to improve my chess skills, which eventually enables me to win/draw more games.
  


These are good goals, although you might want to add "to have fun" because if you don't have fun you are quickly going to lose motivation.


  I do not care about my opponents' fun.


Also good, because if you care too much about your opponents' fun you will end up losing focus and not follow your two stated primary goals.


  Is the idea of destroying your opponent's fun good?


No, it is counterproductive. If you start focusing on how much fun your opponent may or may not be having then this can only distract you and detract from your game. If, for the purposes of this question you are going to be truly self-centered then you cannot let your opponents' feelings, good or bad, enter into your considerations. It can only lead to bad play on your behalf. Concentrate on making the best moves.