I think one of the causes is that a lot of CS is taught top-down and not bottom-up, so things like flowcharts, state diagrams, and other similar visual aids are completely skipped in preference to more abstract thinking. I wonder if at least some of this aversion is directly related to the "gotophobia" that started with Dijkstra's famous paper.

It may seem difficult and tedious, but this is how you engineer something rather than merely 'develop' it.

As someone who learned the "old school" way of planning out your code --- yes, even drawing flowcharts and state diagrams --- before writing a single line of it, I can assuredly say that it should be a natural and completely pleasant process; what's "difficult and tedious" is trying to debug and coerce something you (or someone else) wrote without planning into working correctly.

Over the years coworkers have been puzzled at why I spend "so much time" flowcharting and just thinking before writing even a single line of code --- only to try adopting the same method once they realise how much time it saves in total, since all the cases have already been accounted for and the only thing left to do is test out any of the few remaining and often trivial bugs introduced during the design->code process.