I am writing here from a student's perspective
You don't earn respect as a teacher on the basis that you did your B.Tech. from IIT or not, or other parameters, such as good looking or well dressed or fancy car, etc. Honestly, while studying in IIT Delhi, I did not even know which college the professors did their B.Tech. and I don't think most of my classmates knew about it either. What to speak of B.Tech., I don't even know where they did their Ph.D.s from.
Only thing that mattered was how they treated their students and how sincere they were towards their teaching. It does not matter if someone is a Nobel Laureate, if his teaching skills are found wanting, the students will not respect him much as a teacher, they may respect him as a great scientist.
Unfortunately or fortunately, this is how things work in this world. You are judged based on your present performance. Your past can only give a good first impression, but to get sustained respect, you have to be good at the job at hand.