I discovered this tirade in a seminal string pedagogical work:
'It is most regrettable that our present-day instrument-makers take so little trouble with the finish of their work. (Most instrument-makers, it is true, work nowadays merely for their bread, and in one respect cannot be blamed. People demand good work and pay little for it.) And what is more, each works away according to his own notions and his fancy, without justification for either one or the other... They all decide the height, thickness, and so on by the eye, never attaining any fixed principles; so that while one succeeds the other fails. This is an evil which indeed robs music of much of its beauty.' Fortunately for today's makers, it was actually written by Leopold Mozart in his Treatise on the Fundamental Principles of Violin Playing. He wrote it in 1756, nearly 20 years after the death of Stradivari, and 12 years after the death of Guarneri 'del Gesù'.
Today's violin making is in a much healthier state. There are great luthiers around the world making beautiful-sounding instruments – and the finish of these instruments is often awe-inspiring. And rather than all of them following their 'own notions' many are inspired in every detail by Stradivari and 'del Gesù'. Some would argue that this devotion has gone too far and is stifling further evolution of the instrument.
That reminds me of one of my favourite jokes. How many violin makers does it take to change a lightbulb? One to to change the lightbulb and 23 to sit around discussing how Stradivari would have done it.