Why is attendance policy not necessary? I have already shared this incident in a previous answer.
So, let me narrate to you an incident that took place with a friend of mine in Chemical Engineering Department at IIT Bombay. So this is our final (fourth) year, and mind you in this penultimate semester (because of placements) no one really cares about the courses or grades. So, students generally tend to be lethargic about going attending classes and don’t give a flying f**k about attendance.
But then, there are some professors who have to be cranky and grumpy about attendance and cannot let the students live in peace even in the final year. And mind you, the holier-than-thou professors have the power of giving a DX grade (a grade awarded at IIT-B for low attendance and you have to repeat the course in the coming year) if they keep a strict attendance policy.