Some of these kinds of things [...] are actually intended for people who are partially or wholly physically disabled.

After I learned this, I immediately felt bad for poking fun at these kinds of products. Normalizing their use by the non-disabled, and depicting the products likewise on TV, makes it that much more acceptable to the intended audience. If this wasn't the case, it might sting a bit as a gift for someone that really needs it. And then there's the economy of scale effect you mention; nobody would get a Snuggy if they cost $100 each.