I haven't seen any claims that it's a wonderful choice, though I admit I scan read parts.
You'll have to take my word for it re the particular vitriol aimed at young mothers. I have had direct experience of it myself in RL, I'm guessing you haven't. I do see echoes of it on this thread, however.
As for injections of realism - teenage mothers have enough of that. We're all perfectly aware of the realities. That doesn't mean our lives should be doom and gloom from the moment of conception onwards. Women have come on to this thread repeatedly and said "yes it was hard, no I wouldn't recommend it, but actually, I've done OK". That is not whitewashing reality, that is our reality, and as usual some people begrudge us ownership of our own lives, because they are so fixated on putting us in a box.
In a wider context, I feel its an example of how women, once they deviate from any kind of social norm/fall from grace, are simply never forgiven. Perhaps teenage mothers get it more because their "sin" is particularly visible. I'm perfectly aware that I'll be judged for the rest of my life based on decisions I made aged 15, this despite ticking the other boxes of a nominally successful, at least respectably ordinary, adult life. People can see "where I went wrong" very quickly, certainly as soon as they see my DC and do the maths. I honestly do not feel, at this stage, that the age I gave birth defines who I am, but many other people seem to disagree