Eddie Murphy had to be part of the Star Trek universe.
In the ’80s, a Star Trek movie was going to be made, and one of the writers found out that Eddie Murphy was a fan of the show. At the time, the actor was hanging out at Paramount studios and was often seen, so a special part was written for him. His role was to be that of an astrophysicist, but the scenes were never used because they decided to give the plot another twist.
Of course, this hand gesture means "read between the lines"...
He came up with it for the character. He's the reason it's in the show. That's all that anyone needs to know. Pointy ears weren't a new thing, either.