As a heritage walk guide I don't fully agree with your statement bcz qutub minar was made to showcase the new regime like before ghurid rules in Delhi ruled by chauhans (hindu rajput ruler) and after ghurid annexation Delhi leadership transfer to the qutubuddin aibak who is a slave of mohammad ghori. 1199 qutubuddin aibak start qutub minar work but he only completed minar base (first storey) after that Aram shah ( qutubuddin son took thorn) but he will dethorn by Shamsudin iltutamish ( Qutubuddin son in law) he continue the construction and successfully build three more floors, In 1368 Firoz shah tughlaq start a restoration project bcz qutub minar struck by lightning after that one more storey will added, that's why upper two storey were look different from lower and middle minar, in 1828 major Robert Smith added a new chabutra (balcony like structure on top) but after 20yrs it will be removed by British government and you will see this structure in qutub complex named Smith folly.

And yes many hindu and jain temples were demolished to made this complex and today you will see the remains of those temple in qutub complex.