I can't say that my immediate reaction on listening to this wasn't wanting to say a good-natured HTFU, but you know, the honest admission of not being thick-skinned about things and actually making a video to deliver your message sold me a bit.
Cliques form everywhere, it's human nature. Because these cliques are disseminating information between members (pretty much by definition, because the cliques form up and maintain cohesion by that communication), strong opinions on outsiders will quickly get translated to everyone in the group. Open contact between groups tends to break up such negative images though, as I'm sure any attendee of a Fan Fest will tell us. This video was an example of such open communication btw, so good on you.
In Eve or any other role-playing environment, things get doubly complicated because of our characters. We don't only display our own personality, but that of our characters. It isn't and shouldn't be a surprise that we allow someone's character's personality to influence our view of the player. That's to a large extent how we are wired.
It is also complicated once again by the fact that not everyone is role-playing a character very distinct from their own personality. They are playing their avatars in the virtual world and not a separate character created with what could be called a more authorial viewpoint. An avatar role-player will also tend to assume that other role-players are like him, just as a non-roleplayer might when reading a role-players impassionate defense of something like slavery and assume that opinion as the player's. When we meet someone in game or read their writing, we necessarily don't know what type of a player we're dealing with.
So, when viewing the community, the characters themselves are moving, the players are moving and the ground is shaking. It's difficult to get your bearings and impossible to fully control how others will react to the myriad things. You can only control your own communication, which will then by necessity have an impact on the rest of the community.
My advice is to have a thick skin and for those for whom it doesn't come naturally it is crucial to understand the above dynamics and expect that you control only yourself. In addition, people tend to be very keen to jump on any argument. I'm not going to say that don't do it, but that when you do it be very clear what you are arguing about and on what level. If we're having an argument about slavery for example, we will get nowhere if I think you are an idiot for believing slavery is cool and you think me obtuse for not recognizing that slavery is a part of the Amarr Empire and the game we play.
But even after all that, there will be some people who won't like you. They will embrace the power of the Internet and be an idiot, too. I'm perhaps lucky that I am indeed quite thick-skinned (or that I perhaps have "the sensitivity of concrete" as Ashar kindly put it). But it's not just thick skin (or a lack of functional brain matter)...
I recognize I play a game with complicated interactions. You can get caught up in an interaction with me that leaves you thinking I'm an utter twerp. It's too bad, but I'm okay with that. I don't need validation from this community to feel good as a person (but I'm not saying that validation doesn't feel good).
Indeed, I think that's the key to the whole mess. We all need communities that provide us validation and indeed make us feel good as people. We really do. I would hope that most people have such in RL. Eve being a cutthroat game about a rather dark universe with a whole host of antagonistic and disturbing interactions at its core game-play and flavor is definitely not a good place to come find that validation and peace of heart.