Why do French put masculine and feminine?

Answer 1

Because they have no word for "it." Everything in the French language is either a boy or a girl.

Answer 2

In French, nouns have gender (masculine or feminine) which is a grammatical feature. There isn't a specific reason why certain nouns are masculine or feminine, it's just a part of the language's structure. Learning the gender of nouns is important for correct grammar and agreement with other parts of speech.