Why Does Ruger Still Offer a .38 Special SP101?
Easy answer: Because for whatever reason they still have a market. If or when sales drop (if they ever do) they'll reconsider. Sales numbers and market studies will always outrank Internet forum's opinions.
Of course this can go two ways. The SP101 started life as a .38 Special, but became a .357 Magnum when requests from the marketplace ask for it.