So why is this an issue? Beyond the fact that there are more than enough "Debbie Downers" in the world, and we certainly don't need to allow ourselves to become one, there's some theory that would suggest that this could be bad for our mental health. You see this discrepancy between the real and the ideal has been examined for a long time in the history of psychology. Carl Rogers, a noteworthy figure in psychology, had proposed that many of the issues that we struggled with had something to do with us having a discrepancy between our real self and our perceived ideal self. Think about this, where do you get your beliefs about what makes a perfect you? Are they yours? Or are they some evolution of what other people have placed on you over your life time? We often fall victim to believing that we aren't as "good" as we'd like. Rogers saw this personal struggle between what we wanted to be and what we actually were as being toxic. He believed that when we were able to feel OK with who we were, and feel what he called "Unconditional Positive Regard" we would begin to heal. The evolution of this is that someone else (in Roger's case he believed that was the role of the clinician) provides us with "Unconditional Positive Regard" and then we develop for ourselves "Unconditional Positive Self Regard." Makes sense doesn't it? If you feel like there are other people in the world who simply like you for who you are, then it becomes easier to accept yourself for who you are.
I want to suggest that the more often we involve ourselves in negatively critiquing everything that goes on in the world, the more likely we are to become overly critical of ourselves. This may not be something that we admit to readily, but I believe that we ascribe our own meaning to our actions, and so if we're always being negative how easy would it be to turn that negativity back on ourselves without realizing it. There are studies out there that identify this notion that the more negative ways in which we interact with our outside world the more negative a self image we have, but likewise the more positive things we do and say the more positive our self image. So perhaps the next time you're playing a match of Halo and your teammates aren't quite holding up your end you can offer them a bit of encouragement rather than rage quit while insulting them (or perhaps just quit quietly if you aren't someone who can muster up being overly nice). Or perhaps when your friend is talking about how awesome that trailer for the next installment of "That Game Series You Really Hate" is, you can manage to find something even very small about the prospective game that you can point out as being reasonably interesting to you. We gamers are all in this together, let's choose to enjoy each others company around this media we love, rather than bring each other down.