[kahrkunne]

Yeah that's why they do that in schools all over the world- oh wait...

The best way to learn a language is still to memorize grammar and 2000-3000 words, then read.

[gkya]

They do so because it's impractical to do one on one lessons with a classroom-ful of people. You can believe what you want but there is a lot of research on the subject that supports me instead of you. See e.g. Krashen.