Getting too excited doesn't seem like a good excuse to me. Getting too excited would be saying "boom!" or "I'm the greatest!" out loud while you're playing, and it wouldn't bother anyone on the opposing team because they're not there in your house to hear it. When you make the decision to actually type the comment and then actually do so, those overt conscious acts take you out of the "too excited involuntary response" excuse. Such behavior is that of a poor sport and a jerk, in my opinion, unless you also compliment them when they crush you and make sure to offer such compliments at least once a match to those you are gloating over. Obviously, judging from the reaction here, a lot of people disapprove of your comments. You might want to think about that.