When I was learning the piano, I found that so many teachers, of both piano and music in general, focus on only the playing of a piece correctly without giving the student a real understanding of what is is that he/she is playing. I have heard too many times at beginner level 'because it just is'... when a student asks a question.
I aim to answer every question I am asked about any area of music. My philosophy as a teacher is to give all of my students a real understanding and appreciation of music as a whole subject. I believe strongly in integrating theory into a piano lesson rather than seeing it as a separate subject. I also think it is important to understand the context of what is being learned, historically and musically, as it helps the pianist to get the most out of each piece.
I have found that this approach to music teaching instills a deeper interest in the subject as a whole and keeps students engaged and practising more.