The original Star Trek always included Spock, the alien crewmember aboard the USS Enterprise. However, Leonard Nimoy's logical Vulcan was never supposed to be the show's central, mythical figure. William Shatner's Captain Kirk was supposed to be the breakout star. Yet while Trekkies loved everyone on the bridge, their greater affection for Spock has made him the most beloved character in the entire decades-old franchise.
Source：https://www.cbr.com/spock-not-supposed-to-be-star-central-character/
