Typical fan: "I dislike character X because she/he has flaws A, B, and C."
There's no right or wrong reason for disliking a fiction character (or at least very few). There are certainly character flaws that push all my buttons and make me dislike the character possessing them (and not always the objectively worst character flaws, even). But it's odd how many fans claim to love characters for the flaws, and then just take it for granted that the reason to dislike a character is that they have flaws.
Your public livejournal/tumblr/other social media is not your space.
It is your platform. It is not your space.
Certainly you can and should have some sense of how you expect people interacting with you blog to behave. You should be the one to decide those expectations, not anyone else. You should enforce those expectations as you choose.
But if you choose to make statements to the world, the world is going to want to talk back. You can't make public announcements that anyone can read and then block and hide from anyone who makes you uncomfortable, anyone who does not reflect your worldview back upon you. You can't pontificate to anyone with an internet connection and then do everything in your power to hide from responses to your words made by people who like TV shows that offend you, or have negative opinions about fictional characters you love, or who respectfully point out that your arguments don't make sense.
Well, you can. But I, for one, will be unable to have any respect for you.
Public social media is not a place where you should feel comfortable.
Safe, yes. Comfortable, no.
Every time I have heard a fan describe a fictional character as an "unsympathetic victim", it has always been a character that the fan has no problem sympathizing with whatsoever.
How convenient for them.
ETA: Okay, clearly I am cranky today. "I[...]will be unable to have respect for you" is a vast overstatement and unfair. It will lower my opinion of you, a little. But there is a lot more to people than how they choose to moderate their social media. My bad.