Because:
1.) It's not even remotely suspenseful and you already know what's going to happen like, 20 minutes into the movie.
2.) Bad acting. And I'm talking EVERYONE in the movie.
3.) People get punched in the face for no reason. This neither fun nor is it neccesary.
4.) On the plus side (or downside, depending who you are), it's got alot of S&M in it. Leather, whips, chains, rope, everything.
5.) It's just.....really....*sigh*....just bad, please don't watch it.
6.) The dialogue is repulsive and badly written.