And I'm not talking about the text, which is in fact poorly written.
And I'm not talking about the sex scenes, which, you know, to each their own. You like being spanked, go ahead. Nothing wrong with that.

SPOILERS!

The real issue with this series (I only read #1, and then read summaries
for the other two) is that it presents an abusive relationship as ideal
and romantic, thus perpetuating the idea that it is fine to have a boyfriend that:

- Gets mad at you for, like, everthing (including rolling your eyes,
biting your lips, not eating three meals a day, going with your bestie
for some drinks after work, working or visiting your mom).
- You are afraid of (of course, he's getting mad at you daily so it makes sense)
- Orders you to eat, accept an unwanted present, always wear the clothes he likes...
- Marries you and says 'finally, you are mine'
- Gets jealous of every guy that says 'hello' to you and prevents you
from being with your own mother (she needed to be away from him for a
while and told him so, yet he felt the need to stalk her down to Georgia
and she was fine with it). Yet he can meet whomever he wants and have
periodical dinners with an ex-lover.
- Buys the company you work at
because 'it is safer' and forces you to assume his last name
(professionally, I guess she already accepted it in all other spheres)
- You are scared of telling him he got you pregnant because he might get
mad. He doesn't get mad, but just leaves and goes get drunk and gets
jealous of the baby (no kidding). Somehow she's fine with that, too.
- He spends (at least) one whole book trying to talk her into being
punished, beaten and other stuff. She just doesn't feel like it, but he
still tries to convince her. And of course succeeds, I mean, otherwise
he would get angry.

Do I need to continue?

END OF SPOILER

I mean, this is bad. It's not bad because it's poorly written, or because
it's (rather light and non-evocative) erotica. It's bad because women
all around the world (and especially teens) are wishing they had a
Christian Grey in their lives and think this is a romantic, sweet, cute
(even if kinky) story.

-Now, if these two people had met at a BDSM reunion, had started talking and suddenly discovered they both were into Thomas Hardy and Charles Dickens, and both loved fishing at the weekends, that must be a good, healthy story.
-Or, if this had been the story of a long-term relationship couple where one
of the two decides to, you know, just try new things out, and the other
one had said 'oh, well, why not, we trust each other, we know each
other, we love each other, let's give this a chance'.
-Or, say, this is the story of two friends with benefits who want to explore the entire Kamasutra together and agree to do that on Monday nights.

But, oh, no. Let's pick a girl that has no idea about sex, has never had any
curiosity for sex, has never had any sexual urges, and has a really,
really, really low self-esteem and pair her with a controlling freak
with traumas (as if everyone into BDSM had traumas or something).

To top it off, make her change him into a good, mentally-stable man. How
beautiful. Let's reinforce the idea that a good woman can turn a
jealous, controlling freak into a good guy worthy of her unconditional
love. That way, you can have thousands of women in unhappy relationships
waiting for they men to just change.