There exist a number of kali temples in Bengal from 17th century. Specially, Kalighat and Tarapith temples are famous for being two of the 51 shakti peeths. Moreover, till date there is a tradition of annual Kali puja in many old Zameendars’ (who traditionally used to be landlords) family of rural Bengal. So, the worship of goddess Kali indeed has a deep and old root in Bengal. Now, the question is, why the highly educated and rational community from kolkata follows goddess Kali in spite of having note on some previously existing cruel traditions like animal sacrifice (generally goat) during the worship?
Shri ramakrishna Paramhamsa, whose simple but deep explanations of the Vaidantic philosophy, and immense devotion and faith on the deity directed a considerable portion of the 19th century intellectuals of kolkata towards the way of faith and devotion. His immense love towards mankind exceeded the barriers of castes, creeds and races. Consequently, a large number of his young disciples, led by Swami Vivekananda started emerging from the late 19th century.
He also said that, water remains the same compound whether one calls it jal, pani, water or aqua every name leads to the same thing. Similarly, irrespective of what do you call the god Maa Kali, Allah or Jesus every path leads to the same eternal truth, the same ultimate realization, which can only be attained through devotion.