I can't really stay mad at Sylvie for killing Kang. Imagine being ripped away from everyone and everything you ever loved, and having to fend for yourself alone for years. Loki was blinded by hate and jealousy, and became very bitter in Thor and Avengers, and yet everybody loved him. Yet, when Sylvie is going through the same thing, everybody hates her.
Yes, she was hypocritical in some aspects, but just think about her story like Loki's.
