Knowing nothing about this except vaguely having heard the title. I had to look it up. Here are my observations after about 30 seconds of investigation:
The novel is pulp soft-porn; and badly written. I can tell this without reading a single paragraph of it, simply by the character names. Anastasia "Ana" Steele, Katharine "Kate" Kavanagh, Christian Grey, and a helicopter named "Charlie Tango". Good grief! What a load of bad cliches!
So that in itself ensures that I am unlikely to ever read the novel.
Next, a movie full of soft-core S&M? What a surprise (not). Wasn't that the inevitable next "social barrier" Hollywood was bound to cross? Of course it was.
Not that I care about maintaining social boundareis, because mostly I don't. It's just that any movie that has to sell itself based on it's crossing social boundaries will almost certainly be a movie that can't sell itself on it's social value, it's quality of writing, acting, or plot, or on it's staging, cinematography, etc.,. Which is a movie I am not likely to go see.
Perhaps if it's free, on Netflix, and I'm feeling bored and frisky some evening ...