In terms of sales, marketing, consumer preferences---a whole host of reasons--once the L frame Smith/GP 100 frame Ruger were introduced, Smith and Ruger basically abandoned the K-frame sized revolvers.

Although Smith still makes some K-frame guns, try finding any in stores or ordering them. For all the love affair for the Model 19 on this forum, where are the Classic 19s? The 586 became a Classic model, however---the "Practical Python."