There are a number of reasons. Mother is an urban slang that is used to described an iconic feminine figure.

Referring to Taylor Swift as “Mother” is also a term of endearment used by some fans within the Swiftie community. This nickname is a playful and affectionate way for fans to express their admiration and love for Taylor Swift. It doesn’t imply a literal mother-child relationship but rather conveys a sense of closeness, protectiveness, and appreciation for Taylor as a figure who has had a significant impact on their lives.