I've knows some programmers who are awesome guitarists. They know the lingo, have awesome memory, both for syntax and the workings of their own code, and can type really fast and pound out working code quickly.
But the songs they write are mediocre. That is, they do things the hard way, they create functional but unintuitive interfaces (and APIs), they make organizations dependent on fly-by-night technologies, they meet stated objectives but can't fill in the blanks where users don't know what to ask for, and nothing they create is every attractive or compelling to users.
To be a rock star, somebody in the band has to compose awesome music. That is, somebody on the team has to know how to solve the right problems.