It's kind of crazy how people were downplaying the effects. A movie has 4 primary ways that contribute to its success (or can increase its chances).
1. Marketing - This one's obvious. If you bombard people with ads, you're likely to get people interested in seeing it.
2. Innate/Previous popularity - Superhero movies and new iterations in popular movie franchises have this to go by. A new F&F movie will always do fairly well just because there's always a core group of fans. Or a new movie by popular mainstream director (ie. Christopher Nolan or Tarantino).
3. Critical acclaim - Obviously not all good movies do well, but having good reviews definitely can help a movie if they can't rely on #1 and #2.
4. Word of mouth - This falls in line with #3 as something that can help if the movie lacks the first 2. In fact, Get Out is one such movie that HEAVILY benefit from #3 and #4. Yeah it had one half of Key & Peele at the helm, but people are forgetting they also produced Keanu, which didn't exactly do well.
GITS wasn't going to have 1, and 2 was fairly small and limited to only anime fans and those who had seen the original/series. It didn't have 3 to go on either since it started at ~70, but by release day was sub 60 and still dropping. As for 4, .from the get go people were voicing complaints at Scarlett Johansson's casting and the white washing. Post release it became fans of the original also voicing how it lost all of its original/unique series elements, and we all know that passionate fans are often the loudest and more vocal.