There was no real marketing that was going to get Mother to an opening that would justify its budget.
The WOM backlash is because marketing offered one version of the film and it's something completely different, but there's no way to get across what it is and still put butts in seats.
It's simply not that kind of film. It's another The Fountain: budget too high for a film that's pure arthouse and will probably have a cult following for years to come. It'll make slightly more it seem, for slightly less of a budget. Neon Demon was the same way.
Like folks are talking about "new", but Mother! is more "different". Hollywood makes new films all the time. Moonlight did $65 million. Arrival, Hunt for the Wilderpeople, Hail, Caesar!, 10 Cloverfield Lane, It Comes at Night, Ex Machina, and Room all made money off the top of my head. All were films with some original ideas or presentation.
Films like Mother (and Neon Demon) probably should go the route of something like Okja, running on Netflix or Amazon Instant, where folks are more open to experimental projects.
But no, Mother's poor box office performance doesn't really mean anything for audiences, anymore than it's uneven critical reception does. Not everyone wants to see an allegory for either Christian myth or the process of creation, no matter how well acted it is.