I wonder what the uncomfortable truths that everyone is ignoring are in today's programming world?
The many years spent with C and C++ when there are better alternatives around.
Microsoft Windows, OSX, Linux when Plan9 exists.
OOP.
NoSQL and its total misunderstanding of the power of having a declarative query language.
Cache coherency, ordering guarantees, where we should opt for less.
(No, not even "git push to deploy".)
If I had to hazard a guess, I'd imagine Dijkstra would have a word or two to say about callbacks, given his famously strong beliefs about GOTOs....