The Prasthaana Traya - the Upanishads, the Brahma Sutras and the Bhagavad-Gita are same text books of spirituality, but they gave different lessons to Aadisankaraachaarya, Ramaanuja and Madhwa.
How, it happened and has been an interesting happening.
Sankaraachaarya getting lessons of Advaita, Ramaanujaacharya getting lessons of Visistaadvaita and Madhwaachaarya of Dvaita from same compositions is marvel of Indian spirituality.
And it thus informs us that the view, perception, intuition, experience of and stand taken by the commentator are primary; and the actual texts come secondary in importance and adhering.
Very strange and mysterious study and interpretations dawned then. Smart people will make a comparative study, observation and develop an individual insight. Individuals of lesser competence will faithfully but blindly follow their Guru and related interpretations.
Spirituality so is full of liberty and freedom and no Guru must insist on one's own interested interpretation and deny the seeker room for individual and independent observations and conclusions.
And there is not merely one view, insight, experience and understanding in relation to spiritual matters and still scope is there for fresh understanding and commentary of Prasthaana Traya. Even now there are possibilities for independent interpretations adding to spirituality with the same Prasthaana Traya as source.
Indian spirituality stands for individual freedom in living and getting spiritually enlightened. This must be noted by gurus of various cults of today (and coming generations), which claim ancestry of authority on the Prasthaana Traya; before making seekers and devotees their lifetime followers.
Indian spirituality is individual-focussed and not a mobocracy.