[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.