I wouldn't say the acting is bad. They are all competent actors, we know that from their CV's. If there are faults, they lie with the script and direction.
We can only presume that this is the way the writer and director wished to portray the story.
Personally, I think it's disappointing because the original was so much more challenging. The original did make a lot of people feel uncomfortable, it explored the dark side of our sexual nature.
I think an updated remake of the original would still make people stop and think today, more than 30 years on. The subjects of incest and sadomasochism are still regarded as taboo, and rarely explored in drama. But in this offering, everything is much more superficial, and the characters lack any depth.
There's nothing wrong with this version as a different form of drama, in fact it's quite entertaining. I just think it's a pity, the original stuck in the memory for years, this will be soon forgotten.