Free: Contests & Raffles.
i bet it'd make a comeback if they came out with specs for something like a 3 1/4" chambering that would accept higher pressures than the current standard(kinda like 3 1/2" 12ga has a higher pressure spec than the 2 3/4 and 3"). the fact that we've got light 12ga guns that weight less than a 16ga gun now keeps them kind of obscure(the allure of the 16ga is that it's lighter than a 12 but patterns better than a 20).
The reason there are so many Ruger upgrades is because they're necessary.
I have shot a 16 for almost 30 years and I am set up to load for it. If you are just going to shoot factory loads another site that had good buys is Able Ammo.