Self hate is a very common result of childhood trauma/neglect. Childhood trauma/neglect is very common in every part of the world. Self-hate leads to projection, especially surrounding things experienced in youth (e.g. sex drive, education levels). (For Your Own Good by Alice Miller talks about this in detail)

I'm assuming this background doesn't prevent an adult from reaching Stage 5 and that a person with a drive for self improvement doesn't prevent them from projecting self-hate.

The thought is, everything resembling the pattern of Authority Figure (e.g. parent, teacher, cop) punishing the Lower Class Figure (e.g. child, minority) for Context Appropriate Behavior (e.g. age-appropriate sex curiosity, culturally-appropriate responses) is evidence of generational childhood trauma/neglect (this is how the dysfunctional family that abuses their children operates).

Stage 5 (authority figure) burning their bridges because they think Stage 4 (lower class figure) is bad evem though the bridge is necessary for society to function normally (context-appropriate behavior??????) seems to me to fit that pattern.

Again, can you please pinpoint where it says stuff about burning bridges and that stage 4 is bad? On the contrary, it actually laments that stage 4 was unjustly discredited, hindering the ability of individuals to develop there and eventually further!

I don't get at all the rest about self-hate and childhood trauma. I survived myself a hefty dose of either (am hard of hearing since 2) and just don't see any link there.

>With nothing beyond the discredited stage 4 to look forward to, it is mostly no longer possible for humanities majors to develop a rational, systematic self.

As I understand it, the article says that Stage 5'ers are burning the bridge to 4 because stage 4 is perceived as unsophisticated, but Stage 4 is required to grow to Stage 5. If 4 was required to reach 5, why would a 5'er work to discredit 4 - unless these 5'ers saw their Stage-4 self as useless?

Yes the article says that Stage 4 is necessary - but it also says that some Stage 5'ers are dismantling Stage 4 because some 5'ers think it's unsophisticated.

Unrelated - but oh lord I was at the Salvador Dali museum (Dali being an anti-rationalist artist) a few days ago and you could smell the pretense in the air. I didn't know I was going to the museum that day so I was dressed like a slobby, computer nerdy tourist. So many side remarks from the security guards and regular visitors - projecting their sophistication insecurities onto me! The insecure sophisticated anti-rationalists are real!

This is unfortunate misunderstanding. It's the deconstructive postmodernism that did the discreditation of Stage 4. Author in the paragraphs after "Deconstructive postmodernism" explains that first postmodernists were okay because they understood stage 4 rationality and they actually made forays toward stage 5. But their most vocal followers did not understood stage 4 at all and so they bastardized it.