Creativity in making melodies is important for a
musician, or more specifically for a composer. Musicianship in that regard is good to have for a guitarist - after all, it's a definite boon for improvisation - but skill IS of primary concern. I don't know about the rest of you, but I would far rather listen to a highly skilled guitarist bringing life to a composed piece, than some fumbling beyond which can be discerned a creative melody.
The key question is what constitutes skill, and of course the answer is a frantic waving of the arms and the imploration, 'NOT SPEED!' Skill is the ability to execute a melody - whether a result of your own creativity or some other's - with a variation of sound and pace, with a texture appropriate to each note, which completes the emotion that otherwise can only be partially present in a well-conceived melody.