And the part you miss is many of us don't care either about what you do either, but some actions seem to step on toes. Not reading the long book is fine. Complaining that the book is too long and how the book should be the length you want, not so much. I "casual" a lot of things, but I respect those that go more hardcore and I don't see the hobby as something that has to cater to me and my schedule or will. Hence "casualization" as an issue because it can dismantle things that enable those of us that want larger challenges due to the fear of casuals being left out of something. It can come off like "I don't want to work as hard as you for something, but I still want it," which when followed with the idea the hard work at a hobby is something doing it wrong, can feel like tolerance for each other isn't the goal, but domination of the hobby.
And why is the self esteem for hobby accomplishments not real? If I climbed a mountain I wouldn't be judged for that, but other than the skill set used, what's different than in beating a video game on the highest difficulty level? Both are about seeing a challenge and overcoming it. Self esteem often comes from one's accomplishments, and while they aren't the most important of accomplishments, it isn't as though they aren't real ones, be it the skill to face the hard game, the perseverance to continue when it stops being immediately fun, and even the occasional transferable skill like tactical thinking, problem solving, or just knowledge retention and retrieval.