At the moment it has 60+% and that makes me happy. I spent a lot of time defending Alien 3 as a stellar addition to the franchise. And, honestly, I think a lot of the hate on it is because of the fate of those that we grew to know and love from Aliens.
The Dog concept was cool. It gave the alien a great new spin. And David Fincher...seriously, his style fits the franchise so well it's unbelievable. It is bleak and stylistic and it fits great into the world of Alien's future...in a Mad Max kind of way.
It was the Alien movie that the 90s deserved, unlike Resurrection.
You have a film that is darker than Aliens and a lot more horror. It fits more into the mold of Alien, with a darker theme. It's a nice departure from the over-the-top Aliens mega block buster action film, and brings the franchise back to it's singular alien ground point.
It works very well. It just followed Aliens and I believe that people were expecting more action, more xenomorphs, more everything. Alien 3 gave you less in the same way that Alien did, and the pay off is there...so long as you don't walk into it expecting space marines.