Right but the higher concentration of complex sugars means you need longer to get to the desired attenuation, making longer secondary fermentation almost part of the style. Beyond that, most stout gets bottle or keg conditioned for several more weeks, as this really aids in development of the desired complexity. I used to work at a brewery and did BJCP training and "young" stouts tend to have a very obvious flavor profile most people don't like. With other ales, we would turn around a batch from grain to cans to sales in about three weeks, but the stouts were more like a 2 month process at minimum. Our best selling gingerbread stout basically took all year to brew. Most breweries treat stouts like the special occasion they are because doing so produces something incredible, and rushing it produces something mediocre.