Nope, no one is making me think anything. I judge her by her deeds and her internal monolouge. No matter how much caps you put down to make yourself believe it, everything Sylvanas has done since she was freed from Arthas control was for her own selfish being: She murdered, raised, lied, genocided, used innocents in human trials of her new blight... These are the actions of a villain. You have to be completely blind to look at any of her actions and deem them anything else.
She has Free Will ever since she got freed from Arthas control. Everything she did after that is completely and utterly her fault. There are several Undead (without the bonus of a fully restored body) that chose to help people in the world, like Alonsus Faol, the Death Knight player character and the Ebon Blade. Saying that Sylvanas had to be evil because she is undead is nonesense, she had the choice to do something positive with her unlife, but she CHOSE not to.
This is not a thing of BFA, she has just been more guarded about her crimes before, now as Warchief she could not hide behind the Horde anymore. She has enganged in brutal murder and genocide long before BFA came around.
There is the snag. Sylvanas got a wiff of what awaits her after her death and you make it sound like her only option is to be a cold-hearted monster only focussed on her own survival, that however is untrue.
There was two ways she could have gone. The first and easier one is to cling to unlife and do whatever it takes to stay alife no matter who she has to murder for it. The other much more painful way would have been REDEMPTION. She could have chosen to change her life and do good with her considerable powers and thus EARN her way into a better afterlife.
She has literally been given a second chance when she jumped from Icecrown. She was shown where her path would lead after the crimes she commited and then she was given the option of changing it. She chose not to. In fact, she chose to become even worse. She deserves everything coming to her after that point.
It's like in the "Christmas Carol" if Scrouge, after being shown the future, said "Yeah, nah, I stay as I am. Maybe I should burn down an orphanage."
You really need to stop making your own headcannon. Read what has been written about her, long before BFA. Read "Edge of Night", read "War Crimes". Sylvanas does not give a crap about the Forsaken other then as her personal shield against death.
She was a victim in the past, but when the victim starts genociding other races with biochemical weapons the victim card no longer works. She has free will. No body is controlling her, she is thus responsible for her own actions.
Did you forget how she blighted Gilneas and thus murdered a good part of it population while forcing the rest to accept the worgen curse as their only way out?
Did you forget how she then proceeded to assassinate Greymane only to murder his son instead (a fact she has been happily gloating over for years now). Did you forget how she was going to use her own sister to assassinate Garrosh, keeping herself blameless in the process and then planned to murder Vareesa and her children too damn them to a life in undeath as well?
Open your eyes. She has always been a villian, the entire time. Even when she was still an elf she cared very little for the other elves under her command.
I personally think that people who think her character changed in BFA have been willfully blind to how she was before. No protrayal, either inside or outside the game ever reflects this Hero Sylvanas that you claim exists. The only people that like her are the Forsaken, who simply had no other place to go and in many cases are of as rotten a character as Sylavans herself (the Royal Apothecaries are litterally evil scientists playing with deadly plagues and testing them on captured humans for fun).
So yeah, explain to me how all the monstrous crimes she comitted long before BFA do not make her a villain.