Why we do not touch papers, books and people with the feet ?
Knowledge is sacred and divine as per our holy books and as per our culture. So we must give respect to knowledge every time. In modern days we have separate subjects as sacred and secular, but in ancient India every subject academic or spiritual was considered divine and taught by the guru in gurukula.
The custom of not stepping on educational tools is a frequent reminder of the high position accorded to knowledge in Indian culture. From an early age, this wisdom fosters in us a deep reverence for books and education. This also the reason why we worship books, vehicles and instruments once a year on Saraswati Pooja day, dedicated to the Goddesss of knowledge and learning. In fact each day before starting our studies, we should pray:
Varde kaaama roopini
Sidhirbhavatu me sadaa
O Goddess Saraswati, the giver of Boons and ful filler of wishes,
I prostrate to you before
Starting my studies.
May you always fulfil me.