I think the scaffold metaphor remains the most pertinent one when trying to discuss the value of technique, such that both devices allow the artist to "reach" places that those without access to them cannot.
Yet, with increased "height," the project becomes more difficult and dangerous for the artist; too, there is the potential that, when working at such lofty "heights," the artist loses his sense of perspective, and forgets that his audience will be looking at his work with their feet planted firmly on the ground.
Ideally, technique is nothing more than a means of achieving a musical/artistic end. Unfortunately, many musicians think that "being technical" is the goal in itself, without thinking out the purpose for which technique should serve.
In other words, there is nothing wrong with virtuosity, so long as the virtuoso is not simply using it to cover the gaps wherein he has failed to create real musical content.