Just because playing a certain way is high risk, does not mean it is a punishable offense. With high risk sometimes come high rewards, and like others have stated, singed was practically designed to be able to proxy farm. Remember, this is a game with only two outcomes: win or lose. You don't have ties, there are no other outcomes, there will always be a winner and a loser. Sometimes you win games, sometimes you lose them; just because you play a champ a certain way or in a different role, does not make it 'troll' or 'wrong', only different than what you are used to.
Remember, anyone can intentionally feed with any champion in any role if they really wanted to; you don't have to be 'off-meta' or whatever to be a troll, you just have to be a troll.
Also in regard to proxy singed -- as one of my main champs and the most games I have this season, I can honestly say there are many, many games as singed where you will go like 1-10 or worse and still win the game, due to map pressure and helping your team get stronger on other areas of the map while you demolish the enemy turrets/base. It's just the nature of the champion and the best method to using him. He's a disrupter class champion made for this.