At least in Finland, there has been a trend of forest owners to favor faster growing species or just felling them earlier. Most of the trees won't be good enough for quality lumber so it's just sold at bulk prices to paper mills. With the method you can probably get 2 good harvests in the time of one. If you let the tree grow 100 years instead of 30, you might not still get 3x the price and you would have to wait 70 years more.