From The Washington Post: “Americans are abandoning wired home Internet”. According to the article's source it's not just one particular social class, but it seems more widespread that ones are relying on their mobile and wireless networks verses traditional wired networks.
We should pay attention to this, because (if anything) this proves that we need to pay attention to how large our websites are becoming. Assuming website visitors can “handle the loading” isn't a conclusion we should jump to. Looks like we need to realize more people aren't using the fastest connections, regardless if they are on their phone or desktop. I know I just said that and I presume web developers (probably including me) will continue to ignore such advice, like we've been doing for the last couple decades.