The inclusion of this article in the Indian Constitution was necessary because a lot of discrimination was going on in the country in the name of caste, religion, race, sex and place of birth since centuries.
Caste system was one of the major social evils prevalent in our society. The way one was treated was mainly based on the caste he belonged to. For instance, the Brahmins were considered upper class people. They were respected by everyone. They got the best jobs in the society and enjoyed a good lifestyle.
On the other hand, the Shudhras were considered inferior so much so that they were called the untouchables. People from the other castes looked down upon them. They were not allowed to enter temples, restaurants and other public places. They were involved in menial tasks such as cleaning and sweeping.
Similarly, the condition of women in the society was very low in the pre-independence era. They were mostly confined to the household tasks and not allowed to go out and work. Girls were not even sent to school. Discrimination was also done based on other mentioned factors, that is, the place of birth, religion and race. It was important to stop such discrimination.
Article 15 also allows for special provisions for the weaker section of the society in order to strengthen their position in the society.
Thus, the inclusion of Article 15 was important so as to give a fair chance to everyone so that they can grow and develop the right way. Article hopes to completely eliminate caste, gender and origin based discrimination one day, and making India a country where all citizens are treated equally in terms of opportunities and fundamental rights.