Elsewhere I had written about how the Metro might not end up reaching certain places, leaving dark areas on the city map. In addition, the further the Metro reaches to the far corners of the city, certain market and villages are bound to be ignored because it is no longer practical to travel to them.
This is similar to the coming up of a flyover (in a city) or a highway (in the countryside) that may bypass certain areas leaving them destitute over time. As a pedestrian or a cyclist your experience of the city is bound to be different. In the 80's just before the Maruti boom, I remember walking regularly through Regharpura to go to Ajmal Khan Market. When the cars came, most of the village lanes were too small for them. So you ended up taking the main roads and slowly forget that these places existed.
In the case of Metro, one example is Panchkuian Road. Ten years back, it was the biggest furniture market - a one stop shop. Then two things happened - branded stores came up in Malls and also along the Mehrauli Gurgaon road. They began to offer better stuff to the people in South Delhi. But still people from other parts of the city came here. Then came the Metro. Although the shopkeepers protested, the line was built.
Today as one rides the metro to CP, one can see the shops lined up along the sides. There are very few customers and mostly the shops have become godowns. One can see rickshaws and trucks loading stuff but the earlier experience of going to the shops and walking along the road is no longer possible.
With the South Delhi line extending to IIT, will this happen to Yusuf Sarai market? One crucial difference is that the metro line there is underground, so for all practical purposes the area above will remain the same. One can still window shop walking along the road. Maybe if they had done that with Panchkuian Road, it may have survived.
But since the Metro stations are going to be at AIIMS and Green Park, will people walk to Yusuf Sarai?