Languages generally develop organically, following changes in culture. But sometimes we have to purposefully change our language to create the culture we need.
Take, for example, sexism. In English, seeing the masculine form of a word—e.g., adding "-man" to a job title, and using he/him/his pronouns—as neutral had been accepted as the norm since the 19th century and still often is. In the 1970s, however, women began to demand equal representation in all things, and that meant in the language, too.
Studies have shown that people are influenced by the words they see. In one study, people were asked to read a story with the following sentences in it:
“The foreman reassured himself he had made the right decision.”
"The foreman reassured herself she had made the right decision.”
When people read the first sentence, they continued on without thinking about it. When they read the second one, they stopped and went back to check that they'd read the sentence right. So masculine forms are clearly seen as masculine, not neutral. It's time to change the language to let everyone in.