Is the sudden h8 generated for vriska justified. She did one bad thing and suddenly she's the worst person ever, because Jake is a little bitch who needs to step the fuck up.

Now the answer to this is a double wammy so hold on tight.
Part of the hate is because this is exactly how Vriska has always been and keeping her alive in this timeline was supposed to allow her to go through the redemption arc she was cheated out of before. So after the time skip everyone was excepting her to be better and then she goes and kicks Jake into the metaphoric dirt for no reason when Jake was already the lowest he’s ever been. It was really uncalled for and peeps are disappointed that she didn’t change.

And for your info, that “little bitch” has gone through a break up, got yelled at by his good friend, got turned into a trickster, DIED, was taken prisoner by his good friend and told he was stupid and only good for his looks and making children, was objectified by the brain ghost of his ex-boyfriend and had his suffering ignored by the same ghost who told him to just man up, then he had to deal with Roxy’s death all in one day. And now he’s surrounded by a group of strangers. He’s literally never been around that many people before, let alone people he doesn’t know. He’s freaking out. He’s suffering from some straight up social anxiety. Tavrosprite comes up and tries to comfort him and Vriska tells him to ignore Tavros and that he’s worthless. So yeah, the h8 on Vriska is justified.