What have we learned from a random LW person opining about things (s)he likely has no experience with?

Not much either, but OP does say true factual things which can be easily checked and which do in fact undermine the claimed benefits of conferences: particularly how lectures are horrible forms of communication.

See, e.g. Scott's critique of sneaky pharma practices. I would think this is obvious enough to not even need saying (but I wonder sometimes...)

Yvain is a self-selected critic. In the mean time, there are countless psychiatrists who engage in the practices and see nothing wrong with it and predictably justify it in the same terms CellBioGuy does, and you would learn as much asking them. What distinguishes them? It feels the same way from the inside.

See also: peer review is terrible, frequentist statistics is terrible, academic career structure is terrible, etc. etc.

Dem's fighting words. Peer review is terrible, frequentist statistics as applied usually are terrible, etc. And this is especially clear when you are on the outside looking in, with no need to pretend to politeness or worry about antagonizing peer reviewers (as one n-back researcher told me) and you can smell the rank careerism and watch the desperate evasions of researchers sensationalizing their findings and have the leisure to watch the replications unfold. (I commonly find that the more I learn about a topic, the worse peer-review papers are and the more important replication is; I've commented often about dual n-back and how Jaeggi has earned tenure & a lab for a non-result, but to give a more recent example that still rankles, on the topic of black-markets, even the quantitative peer-reviewed papers typically range from junk to 100% steaming bullshit like Dolliver's*, and I know this because I have access to multiple independent datasets I can replicate claimed results on.)

* fun tidbit: Dolliver says she can't possibly share her scrape of Silk Road because she signed an NDA.

I don't think academics are incentivized to hide flaws in academia enough that they are just silent about them.

This strikes me as laughably naive: but that's exactly what they do! What I hear in private is remarkably different from what I read in published papers, and if academics didn't remain silent routinely, based on the surveys about how often they manipulate or engage in other questionable research practices, we would be seeing thousands of whistles blowing every day. Which we don't. This is the norm in every profession: you don't air your dirty laundry in public.

Plenty of academics criticize plenty of aspects of academia openly.

What can be criticized is very limited, critics are few, and in practice little ever changes. There's a lot of pressure to conform and be quiet. No profession likes whistleblowers. Oh look, another example of the pressures to not criticize or rock the boat from last week: http://nymag.com/scienceofus/2015/05/how-a-grad-student-uncovered-a-huge-fraud.html

Most important, in Broockman’s opinion, his experience highlights a failure on the part of political science to nurture and assist young researchers who have suspicions about other scientists’ data, but who can’t, or can’t yet, prove any sort of malfeasance. In fact, throughout the entire process, until the very last moment when multiple “smoking guns” finally appeared, Broockman was consistently told by friends and advisers to keep quiet about his concerns lest he earn a reputation as a troublemaker, or — perhaps worse — someone who merely replicates and investigates others’ research rather than plant a flag of his own.