OK, I understand: Sakuracon is run by bad, abusive people. I verified the facts of the case and Omo's narrative checks out completely: Sakuracon management took down a parody of their awful commercial.
Inevitably, I asked myself, would I cancel my plans to attend over something like this? And surprisingly... I think I would. Their mistake is to let the scandal to explode so far from the con date. I don't even have air tickets yet, what to say about the hotel. But if this happened in July, I would still come ... this year, and not return for the next year. Yes, I'm this vindictive. Not sure how common it is among fans though. Probably not very. Usually it takes way more than general assholery in the management to sour people on a convention.
UPDATE: A commenter at JP/Hinano's post posited an obvious discourse: that it all was the cunning viral marketing campaign, because it produced the desired buzz. It puts Sakuracon on people's radar. Those who never even heard about it begin thinking: "hey, they seem like marketing geniuses, bet these organizers are good at organizing and will treat attendees with dignity and respect -- we totally should come".