The important takeaway from that chart is that its opening isn't that much lower than many of the other non-ultra hyped movies. Its hard to tell because whatever loser made this chart didn't label his axis worth anything beyond the 1/2 Billion marks.

So what's killing this movie isn't entirely just a bad opening, of which there were plenty throughout the series, but a word of mouth so bad that it isn't picking up any steam. Which means its not "fatigue" effecting it, but it actually being that bad.