Ekho saidbecause that's the way the world works
I believe It would be more accurate to say that that is how you
perceive the world to be. People can only perceive at the level of their own consciousness. Which is why the expression, "That went completely over your head" came to be. The world has gotten pretty unattractive since the beginning of the new millenium, including environmentally. People are more hateful and petty than I've ever seen it (excluding the 50s if you were Black). But having seen it then, it doesn't affect me as much now.
To the OP: no, you don't have to justify your existence, but you DO have to connect with those who have a level of understanding that allows you to do that. It sounds like you're listening to people whose opinions you should be completely ignoring - and you're not. Seek not have the world understand you: seek to see the world as it is and understand IT. It is easier to change things when you understand how/why they are the way they are.