I can absolutely agree that we as a society need to be more accepting of people as they are. However, an important piece of that is recognizing that maybe society is a reflection of the average person, as opposed to society determining what the average person is. If you watch that Brainwash series on youtube, you'll see that time and time again sociologists give far too much credit to society shaping humanity, when society has little impact on how people think and feel.
There is utterly no defending the photoshopping of children (or anyone for that matter), but I absolutely will argue against the notion that the content in magazines seemingly pushing women towards settling down and men towards promiscuity is some kind of holdover of patriarchal society. As I went into a few posts ago, men and women are biologically different when it comes to mating, and these differences combined with hundreds of thousands of years of evolution (biological and social) has lead to men ensuring their genes continue via promiscuity, and women ensure their genes continue via monogamy and sexual choosiness. When you say "they are catering to implicit assumptions from society that exert forces on what their readers do" you are literally giving credit to society where credit is actually due to biology. The reason those things sell is because a majority of the demographic for a magazine implicitly agrees that those are desirable things. I can't stand economics at the large scale, but on the small scale like this, it's a well-accepted and obvious notion that free market products will, over time, become more targeted towards their consumers. There is such a thing as creating false demand, but that's nigh impossible to do with media. If people thought the stuff in the magazines was bullshit, backwards, and they had no interest in it, then they wouldn't buy it.
This is getting a bit into a nature vs. nurture argument, and maybe that's where the heart of the disagreement lies. I hate to reference it again, but those Brainwash videos are really fucking good, and they have one that goes into a few studies about nature vs. nurture, and the science overwhelmingly indicates that nature is the dominant factor at play. Nurture can push us a little bit this way or that, but the majority of who we are is determined by our brain patterns, which is determined by hormones, which is determined by genes.