Roleplaying isn't just about sitting in your circle of people and choosing to acknowledge who you want to, it's about bringing others into it and interacting with your surroundings.
Wrong. Roleplaying is about
playing a role. Whether you play it with a select group of friends or try to share it with as many people as possible is completely and utterly irrelevant. I think the word you might be looking for is community, and even then you're well off.
Look at any community in the world and you'll find self imposed segregations. Every major multicultural city in the world has it's own ethnic sub-communities and sub-communties of neighbourhoods within them. You have your own sub-communities of your friends within the region etc.
There is no rule anywhere that says you have to like everyone. You stay in a community because you like parts of it and you help those parts, if you don't like those parts or don't help then you leave the community. You are no more required to interact with everyone's characters than you are required to post on every forum to be a productive and active member of the community.
The reality of the freedom of creativity of the site is simple. You do what you have to in order to create and play a character you enjoy and I will do the same. If you happen to enjoy playing a blue haired, half-demon paladin of Tyr and want to play a human from a realistic world where there are no half-demons then we're going to have to agree to disagree and allow our characters to exist without pushing in on each other. ie we agree not to ppush our characters onto each other.
You can roleplaying with like characters and I will do the same, everyone's happy and nobody's required to do anything but what they wanted to do.
However, just because a character is semi-unique does not mean that they should be automatically written off from a roleplaying standpoint, but as you've stated several times already, this is not logic, this is interaction.
It has nothing, nothing, nothing, nothing, nothing, nothing to do with being different or semi-unique and entirely everything to do with meshing and matching other people's roleplaying values. To be honest I do not care whether your character is unique or rather standard issue, whether they have a novel of back history written or just a vague concept still forming in your mind. What I care about is can I RP with them without compromising my character and/or enjoyment?
For example:
I like to RP 2nd Edition, I like to include lots of tiny details and base everything my characters can do off realism and complicated logic. My characters are quite compatible with people who are similar in their styles, however they do not do so well with people who like high levels of suspended disbelief and to never let the logic get in the way of a cool event. Ergo I try to avoid such people since it minimises the conflict I'm likely to have with them.
Likewise there was a peroid when it seemed fashionable to have a dragon follow your character around. Given that most of my chars would flee a dragon on sight it gave me the options of (1) stop playing those characters or (2) don't acknowledge the dragons and try to avoid their masters/mistresses or (3) tell the owners to stop it so I could RP without having to avoid acknowledging them.
I chose option 2 and to be quite honest, I don't think most of them were even aware, much less cared, that I did. They were too busy roleplaying with the people who were like minded and had characters that didn't flee at the sight of a dragon.
Now, given all that, there is absolutely
no reason anyone should expect their character's presence should get them
anything from
anyone. I've said it before, roleplaying is a performance art and part of the artist's challenge is to capture the attention of the audience.
Can we help with this? Certainly. But not by telling the audience "Hey! You should be paying more attention to me!".