"Old is gold"
Very well said, but as we know it is risky and sometime very expensive to protect gold and precious things. Just like that old buildings with historical stories and information has the same scenario. Even though government want to preserve historical heritage but it is not easy as it seems to be. There is a lot of money involved in maintaining such type of places. On the other hand new infrastructure buildings are widely under construction because of the today's need. So now here's the opinion rise in my mind, which is for sure that city should not waste money in keeping the old buildings, instead should introduce latest and technologically equipped buildings.
There are a couple of reasons to destroy old structure and replace them with new models. First of all, if city has to retain old heritage it will cost too much to maintain such type of buildings because they are for preservation, for tourists, or may be for history record which is now a days not very important. However they could spend this money for orphanage, for social services or to maintain public parks and it worth.
Secondly old buildings often spread on a vast area and cover a lot of space of the city. They could replace these large areas with new housing schemes or new apartment buildings for people to start living in that area which is just a historic lace telling the same story for since many years or may be with new offices to provide opportunity for job seekers to start their professional life, to begin earning for their self which is productive. So I will go with that opinion to not to keep old but to develop new things and consume that space for good.