I see defenses of the five-paragraph essay which describe the template as "training wheels" for developing writers. I unpack this in "Why They Can't Write" arguing that training wheels are not a help in developing essential skills, but a hack to prevent academic disaster. 
This is true of training wheels on bikes. Research has shown that training wheels actually prevent the development of the most important skill for bike riding...balance. The training wheels function as a guard against children cracking their heads when supervision isn't available
Those bike training wheels may be a necessity so children can get around on a bike without being in physical danger, but experts now recommend children learning on "balance bikes" where their feet touch the ground from a young age. When it's time for a pedal bike, they're ready.
I believe one of the reasons we see the 5PE as a useful set of training wheels is because we fear (with justification) what happens if students have to practice the writing equivalent of balance (making choices) from the get go. None of this is the fault of teachers.
When students are being judged against standardized assessments from an early age, and teachers are judged on student performance, turning to the 5PE is a way of preventing potential disaster. It's sensible, rational, but I argue, it's not helping students learn to write.
IMO, writing is thinking, so anything that keeps students from developing their thinking and making choices ultimately delays or prevents their development. The 5PE is part of a system that punishes exploration, choice, freedom, because of an obsession with "assessment."
The 5PE has a long history that's always tied to assessment. It hasn't always been a part of schooling, however. I'm 48 and wasn't introduced to the 5PE until high school when it was introduced as a hack for AP exams. The saving grace is I'd already learned to think like a writer
When teachers say that students "need" the 5PE, I always want to know what they need it for, and it's almost always driven by a particular assessment, an assessment which may not be well-aligned with the experiences which help writers develop. This disconnect is at every level.
For a good chunk of my own teaching career, I enforced the disconnect by giving students more sophisticated versions of the 5PE in order to prevent disaster in "college" writing. Over time, came to believe I my prescriptions were hurting long term development more than helping.
My own big pedagogical shift came when I decided to look at my approach not as helping them do well on the assignment at hand, but looking more longterm, helping students develop their writing "practices" (knowledge, skills, attitudes, habits of mind of writers).
Taking that longer view often resulted in student writing artifacts that were not as accomplished as when I used more prescriptive methods. That was hard to swallow. But...I could see students engaged with a more challenging and ultimately rewarding struggle. That seemed worth it
As I became more familiar with the research on writing for transfer, I saw I'd stumbled on something lots of folks were already studying. Building a writing practice is just one framework for thinking about how experiences in writing transfer from one occasion to another.
Importantly, I had the freedom to make this shift. Even as a contingent college instructor, no one was breathing down my neck and I wasn't beholden to my students' performances on high stakes assessments. K-12 teachers are not allowed this same freedom.
Ultimately, this is why I decided that the front part of Why They Can't Write would have to examine the systemic problems underlying the teaching and learning of writing. Pedagogy is not a fix by itself. It isn't even the most important factor.
As long as we have a system which privileges compliance and conformity and constrains teacher and student freedom and agency, the 5PE will be useful. When it's a route to AP credit or college admission, it could be malpractice not to teach it.
But this is not the same as teaching students to write. It's training them to pass assessments, assessments which may be important, but which hold little meaning, particularly to students, which turns writing into something alienating, rather than liberating, a big problem IMO.
I do not criticize teachers who use the 5PE, but I will always question what's underneath that "need." Usually when we go looking, we see things that are actually not conducive to learning like standardization and surveillance, which inevitably lead to anxiety, or worse.
We must give K-12 teachers the freedom and power to work with the longterm development of their students in mind, rather than being beholden to these assessments which measure little that's meaningful. Without that freedom, we're stuck in this system.
To come full circle back to the training wheels theme, we have to make it so when students are developing their writing practices, they get to "fail" productively, rather than failure being something like flying over the handlebars and cracking a skull.
With writing, "mistakes" and error should always be occasions for learning, not punishment, and definitely not punishment of teachers. I spent years developing Why They Can't Write, and based on early readers, there's already stuff I'd change. That's exciting.
It's exciting because my ideas are being taken seriously by other people with similar concerns. My ideas matter to me, and them, and those ideas can be made better. Why wouldn't I want my students to have the same joy? It can be done, I believe.
Here is where I plug a forthcoming book which is my attempt to create the conditions under which students can experience similar pleasure with writing. Curriculum isn't going to save us by itself, but this is my best (current) attempt at living my values. amazon.com/Writers-Practi…
And a coda. Here's a link to a dissertation by @jtdavisii which includes a deeply researched and fascinating history of the use of the 5PE. That part starts on P. 53 scholarworks.gsu.edu/cgi/viewconten…
