How can this be rated so high by IMDb?

Rating: 3/10 (28 December 2015)

This film is 2 hours and 49 minutes of slowly bleeding to death. The magnitude of actors is the only one thing that keeps my attention (e.g. when is Matt Damon inserted into this?). Such a disappointment. I'm very pleased that I waited until this was available on streaming services.
The beginning, while slow and lacking character development (and somewhat unbelievable), is interesting. The end is completely ridiculous. I had a flashback to "The Fifth Element" where it was declared that love was the 5th element. Too much time spent on irrelevant side stories that added nothing. The ending is difficult to find realistic or plausible. I found myself wondering how this movie could have such high ratings on IMDb after being released over 1 year ago!
As a scientist/engineer, I wanted to enjoy this film. I was woefully disappointed.
For anyone interested, I'd watch The Martian long before watching this drivel. I'm shocked that this is #29 in IMDb's "Top Rated Movies", how did that happen?
Brings into question how reliable IMDb really is with respect to objective movie reviews.