Not that the two main female characters are billed as representative of anything, but I think the message this film carries is that all men are imbeciles. Selfish, full of their own importance, dishonest and boring. Two victimised women join forces to rid the world of such sharply dressed gits. It's filmed very much like a documentary, the acts of violence conveyed in an unspectacular way (although there's a nice one towards the end).
As a result, things are deathly dull viewing a lot of the time. Language and lifestyle choices may seem quite shocking to begin with, but with nowhere to escalate to, lose their impact and appeal the more we see them. There is a constant backdrop of topical news reports running throughout. There's probably a message there about the corruption of the world, but it's not clear.
A nice twist at the end doesn't really make the previous 108 minutes less tedious. My score is 4 out of 10.