I don't mind kink, it can be fun as a one off, and I dont' mind the mainstreaming of it generally, I'm all for a bit of variety and live and let live.
I live in a city with a reputation for kink and so many of my friends and work colleagues have been involved, one way or another at some point. I don't think some of it is actually kinky as such, some is just people with relationships that cross some boundaries (like the polyamorous triad who are really normal in every other way) and they just get on with their lives. But lots of the BDSM stuff (which DDLG is a part of) has people who aren't just trying something and adding it to a wide repertoire, they're making it a lifestyle. Instead of adding variety and expanding what they experience, it has become a box that they put themselves in and reframe their conformity around.
I find the DDLG kink particularly nauseating but not because I think it's verging on pedophilia for the men. If they were actually attracted to young girls a grown woman pretending to be one wouldn't do it for them. These women are clearly grown women and if you've been unfortunate enough to socialise with a kink lifestyles like this are openly accepted you'll realize that their "little girl" behaviour is nothing like real little girl behaviour, either. Most of the time it's infantilising themselves (and their partners in some ways), restricting the roles with which they interact with each other, and tends to be emotionally quite stilted. The women in particular seem to have a lot more mental health issues around anxiety and self-esteem.
It's really inauthentic yet they think they're being brave and adventurous.
At least, that's my take on it. Nevertheless, I don't think it's a concern in terms of encouraging pedophilia. There really isn't the cross over the name suggests. In terms of danger from kink I'm much more concerned about the normalization of breath play and the use of bdsm as a defense in murder and rape trials.