PREAMBLE: Apologies for the rambling wall-of-text crit to the eyeballs.
On the issue of all gamers being lumped together, that is an unfortunate consequence of human psychology and perception. The good gets mixed in with the bad, and the entire bundle gets perceived as bad. We know that the rational truth is that it's only a handful of bad apples, but, because they are the most vocal apples in the bunch, rationality often gets lost and truth distorted. We can't hide from the fact these deviant individuals exist within the community; we can't pretend there is not a negative side to our community and that it is not included as a part of us. We're all together in this, like it or not.
To this end, and I definitely agree with you quite strongly that the onus is on the community, in my opinion, it is critically important for the community, as a whole, to take strict, decisive, and stringent measures to make it clear and unambiguous that hateful, harassing, and personally threatening behavior can not and will not be tolerated to any degree. Further, the community, in my opinion, needs to find a way to levy some tangible punishment upon the perpetrators to drive this point home. Essentially, the community needs to have a means of enforcing the more positive, mature, and sociable behaviors that we would prefer to see and deterring the toxic, abusive behaviors we don't want to see.
The gaming community, in my opinion, should be an environment for fun, quality social interaction with games as the platform over which that interaction occurs. Our community is extremely diverse, perhaps the most diverse of all social circles. But further, it is a community full of people who have known abuse, bullying, and threatening harassment directly and personally. Thus, it is galling that there would be those who seek to bring exactly such behavior into the community and poison the entirety of the community, inflicting on others the very trauma which they themselves may be suffering (yes, I do understand how those who are hurting will often seek to hurt others; however, in my opinion, that does not at all excuse the behavior). Because of our diversity and personal histories, in my opinion, it is critical that we be more tolerant of the voices, opinions, and preferences of others without the need for toxicity and personal threats. (All these X vs. Y and "my electronic device beats-up your electronic device" tech-religious wars within the community need to stop; yeah, many hate Call of Duty, but a lot of people clearly love playing the game. Let them enjoy it without the crap. If you don't like it, you don't have to play it. Play what you enjoy, let them play what they enjoy, and just move on.) It is critical that we be able to interact with one another in a manner that fosters enlightenment, enjoyment, and edification, rather than trying to tear each other down at every possible moment for every possible little imperfection. And should disagreement occur, which it will because we are different human beings, we need to be able to disagree without being disagreeable.
In any group, conflict is inevitable. This is simply a truth of human beings. The proper path is not the avoiding of conflict; the proper path is knowing how to resolve conflict in a mature , calm, rational, and mutually respectful manner. Often conflict arises as a result of simple miscommunication or a simple mistake. We have to be able to recognize the miscommunication and take measures to clarify the matter without having to resort to personal attacks (such as calling someone an idiot) or threats. Mistakes happen, because we are only human; so, we need to be more tolerant when someone makes a mistake and not sear them with a barrage of personal attacks and threats for their mistake.
I agree, whole-heartedly, that we need to constantly keep in mind that there is another person on the other side of that screen. The rules of human social interaction and etiquette are still 100% applicable online for that very reason. Our words and actions affect them every bit as much as their words and actions affect us. Slow down and take the time to think before you post. Think about your words: how would you feel if someone said to you what you're about to say to someone else? Take the time, especially in a forum because you're not conversing in real-time, to read over your words and give some thought to them. If the words you're about to post were directed at you, how would it make you feel? How would you react? What would pass through your mind? Would you still be having fun in the game if you had to deal with people treating you the way you're about to treat someone else?
I know I'm probably preaching to the choir here, but, we're gamers too. That means we need to take the ideal of creating a better gaming community with us wherever we go and be willing to stand up against the terrible toxic behaviors wherever we might find it. The movement starts small with but a handful of individuals. But, in time, it has the ability to grow and become so much bigger. The ideal can spread as others learn of it and seek it. What starts with but 1 person eventually becomes 2, and 2 becomes 3. In time, 3 becomes 5, then 5 becomes 8, and so on.
It is my belief that much of the toxic behavior we have seen on the Internet in general is because we have let the Internet remain that way for too long. It originated at some point in the past, and those who come into it become immersed within that pool of toxicity and become poisoned to think that this is just the normal course. That being toxic and harassing is just the way you're supposed to be. There is insufficient counter to demonstrate that the behavior is, in fact, not normal and not tolerable. But, that's where 1 must become 2 and 2 must become 3, and so on, to reverse the general toxicity of the Internet, to let others know that this is not the way things are to be. It starts with one voice, but if others are willing to take up the mantle of that voice, it can spread. Eventually, the game community, and one would hope the Internet, in general, can become more the wonderful community that we would like for it to be, without all the toxicity.