It attracts all sorts of people who would love to live in the world of Star Trek. Gene Roddenberry’s vision of Star Trek was to show a future in which we had moved so far beyond our social divisions that they didn’t really matter anymore.
Original series: showed a crew of various ethnicities and origins serving together like it’s no big deal.
TNG: built on that in various ways - with a blind chief engineer, some men in traditionally feminine uniforms, multiple episodes in which they encounter societies with different views on gender roles, and many more.
One of my favorite small examples was their response to questions about Captain Picard being bald, when feasibly baldness would have been cured by then: “in the future, nobody would care”