Mostly what's directly missing is the A to B link. Flashpoint correction > Dante's dead.
It's the same problem I have with blaming Killer Frost on Barry. Given the months in-between, there's nothing to say that Dante wouldn't have died in a car accident in the original timeline. Or Caitlin's powers wouldn't have manifested themselves otherwise.
Essentially, my issue is the Flashpoint/non-Flashpoint changes seem arbitrary and unrelated to the specific pain point of Barry's mother. No one's stopped an asked: "How does Barry's mom being alive against change all of this?"
I don't there needs to be a direct link other than the fact that Barry's time travel has changed enough things indirectly that he can feel responsible for. While Dante dying and Caitlyn having powers could have cropped up later it would've just happened to no one's consequence. Barry going back in time either accelerated the events or made them possible. Diggle's child is huge obvious change because we know for sure he had a daughter.
So yeah people have a reason to be upset with Barry because of the very idea that none of this was the case when Barry left to go save his mother. The responsibility is on him.
But in the same merit both Jay and Oliver(and Iris although she's given more fluff than actually legit advice) tell Barry that he has to accept responsibility for his actions without feeling overwhelmingly sorry for himself because that's an occupational hazard of being thrusted with great responsibility. Constantly trying to fix things the way he has has caused ruptures (as Jay pointed out with the Tea Cup) that Barry just can't fix. And that yes, anyone would have made that decision as we see with Sara in Legends. Sara had the fortune of not being as powerful as Barry when it comes to time travel and changing things and thanks to that she had the rest of the team reel her in. You couldn't stop Barry from making that selfish decision. The onus is on Barry to understand yeah, he's not a God BUT he's been gifted with powers that he has responsibility for. Being a Hero is washed with horrible decisions (Oliver not telling Slade the truth about Shado, Bringing Sara aboard the Gambit, Laurel lying to Lance, Rip telling Savage the exact time and date of his families death, Rip exposing time travel to Vandal Savage, Roy lying to Thea, etc.) but that's all apart of the game.
Its actually all pretty well written imo BUT it has to be due to the stupid decision to do Flashpoint in the first place.