What's a good example of this? :)
Even when babies learn how to walk (assuming a healthy and secure environment) they do not need (or would understand) any assurance that the struggle will be worth it. They go for the struggle because the instinct/motivation to explore is already there - it gives a sense of autonomy, of being in control, of making progress, of being involved, of being alive.
But no need to make assumptions about what motivates babies - you can look at how people feel when playing games, solving puzzles etc. They don't see it as a struggle, it is something that is a joy to participate in, even though it might be very challenging. A great teacher is someone that makes learning a by-product of having fun. I believe this is possible for any subject, no matter how "difficult" or "boring".
No disagreement with any of what you're saying.
But do you have any real life (adult) examples rather than just the equivalent of platitudes? :)
I'm not sure what examples you're looking for or would find convincing. I can speak about my own experiences of learning new things, where the speed of what I learned were always proportional the how interesting and accessible the material was made to be. In the cases where it was made enjoyable, I usually had more than enough motivation and curiosity to dig deeper using new materials that were less fun to learn (but could have been made fun too).
I can also speak of my experiences teaching young people with no knowledge about programming who had preconceptions about how boring and difficult it is, which illustrated the degree of how you teach something has an effect on the perception of struggling.
I assume you have your own examples as well, but if you can offer a counterexample I'll reconsider my opinion :)
There is another important thing I'd like to point out though. What makes something fun or accessible for one person is not always what will do it for another. Having to teach groups, and especially large groups of people will make it very challenging if not impossible to be the ideal teacher. I'm not judging anyone for not being to be an ideal teacher under these constraints. Just pointing out that this should be the objective - not saying it is always possible.