A little late, but whatever. I would wager a lot of the self-taught artists on Twitter have a similar experience learning their fundamentals; they were kids who already liked drawing and took their high school's art class in the hopes of getting better at drawing cartoons. Then some wageslave stooge of a teacher had them draw still lives of random shit lying around the classroom because it meets the state's fine art education guidelines. They weren't told why they did anything or how it would help them eventually draw what they were passionate about, got moved right along through different materials never working in them long enough to gain a mastery of them, and got scolded endlessly by some bitter old crone with 2 eggs left the entire time, so the work they produced ended up shit by fine art standards and boring/uninspiring by their own personal standards.
So "fundamentals" in their world came to mean "boring lame art you see hanging in mortuaries made by people who follow random steps because the state says so." Then they see all the exciting things online done by people who share their interests and suddenly it feels like they've been released from prison and they can finally be free!! No more drawing gradation scales and color wheels and thumbnails without understanding why, because "pfft those don't have anything to do with anime," now they can finally draw what they want to!!!
Is it any wonder they don't want to improve?