Your teachers know and understand stuff you're years away from grasping as a beginner. Its not about being "professional" but rather having the proper foundations upon which you can build knowledge and muscle memory. Its about spending the least amount of effort at any point in your practice so it becomes actually effective. Its about having a logical progression where each new concept adds up to existing knowledge (music theory is VERY well structured in that regard.)
I personally dread that new crop of teachers using MIDI/apps to teach music. This is anything but teaching music - its teaching MIDI and apps. You dont learn to ride a bike by downloading an app or playing "bike simulator" - its just obvious.
Saying "endless learning of grammar" and other forms of "oh god, I have to put in effort?!" mentalities show off a very shallow understanding of the domain - this is what you expect a teenager to say when looking at his courses because he's years away from understanding why they're useful. Sorry to sound harsh but its just how it comes out as.