The thing about saying that something is contrary to classical music practice is that it’s not a fair comparison. Apples to oranges.
Every classical musical tradition has a structured pedagogy that involves you learning mechanics that are scalable from the get-go. With guitar, we don’t have that style of pedagogy - most of what we do is trial and error on an individual scale, or someone trying to explain what worked for them when they’re not even fully sure about what they did that made it work.