[JoshCole]

Cramming the night before an exam isn't the same thing as teaching either. If we need to accept that teaching is always the outcome of the worst performing learners it would follow that schools don't teach children to read. After all, illiterate people exist. That some teaching outcomes exist which are contrary to the curriculums goals doesn't mean that curriculums don't exist.

There are billions of us and learning outcomes are varied in part because teachers vary in skill. With so many chances and plenty of bad teachers, it is inevitable that some small fraction of the population gain the perception that trees aren't taught in CS programs even though they almost always are.

[kragen]

Nobody in this thread has claimed that trees (or sorting or maze generation algorithms, which don't necessarily involve trees) aren't taught. Guessmyname claimed that "programmers who went through college and/or university didn’t learn this stuff there," not that nobody tried to teach it to them. Every claim in the thread about what is taught has been a positive claim that some things were taught; there have been no negative claims claiming that something or other wasn't taught or wasn't in a curriculum.

Teachers can have a significant effect on the learning process, but learners have a much larger one. Other things like available learning resources and institutional incentives may have larger effects than teachers, curricula, or even (variation among) learners.