There is something called Schizoid Personality Disorder, where people genuinely do not feel the need for others, but I'm seeing no evidence for anything like that. What I'm seeing is some people who have been very hurt, who have seen others getting what they wanted, who have been unable to make the connection.
I don't want to sound stupid, but what do you mean by connection?
And they've given up on having anything like that in their own lives,
I don't want to start an arguement or any conflict of that nature, but trying and hoping for the same thing over and over again and expecting different results is the definition of insanity.
I understand that nobody on this forum has perfect health (mental/emotional), although I do know that most people here are smart enough to know that they can't go ahead and play God in order to recieve what they want.
Nobody gets everything they want in their lives, they might get most of what they want, but they can't have everything.
Regardless of having SA or not, obtaining romance is affected by something completely different, something most people on this forum don't know how to operate.
When people give up on this sort of thing, that means they're refusing to let it dominate their lives, they realize that its pointless to try to obtain something that isn't going to benefit them in any possible way.
they've gotten angry at the unfairness of it all,
To be honest, I really don't think its unfair for people not to have something like that in their lives. Something like romantic love is completely unstable, it can't be determined whether it will be a happy experience, or something incredibly atrocious.
I think their anger is directed at love itself, not the people who have it in their lives.
they've convinced themselves it's a good thing so they can cope. It may become so deep-seated that they try to convince others, or reject others themselves to maintain their beliefs, or pride themselves for what once was so upsetting.
Is there something better than being grateful for what you already have?
They may ignore other's happiness and remember only other's failures. They may imprint their own emotions over other's, to ensure that those who appear blissful are secretly unhappy or destined for failure.
A lot of negativity can be generated from seeing and hearing about hundreds of people getting emotionally damaged beyond repair.
They may even reject romantic opportunities, expecting failure, to maintain their own illusion.
What do you mean by illusion?