The internet nerds/hardcore fanboys try to make it sound like it was a big hit, which it wasn't.
It was a critical hit and thoroughly deserved to be one. I look at it the same way I look at Batman Begins, another movie that didn't do all that well considering the marketing, buzz and reviews, but it left an impression and then the sequel became an event.
Maybe the next Mad Max will become a huge hit, but I kinda doubt it. It appeals to a certain audience and it is hard to maximize its appeal across all demographics in every country. Also, some A list actor in the movie has to bite the dust for it to overperform bigtime. That is something I don't wish to happen to any actor whether good or bad.