Only because that subset is artificially limited.
People don't "need" better internet because the ISPs strangle out the competition. Netflix v Comcast was well documented. AT&T meters all of it's traffic, while zero-rating their own individually purchasable items. The current ISPs are doing everything they can to prevent people from moving into the 21st century of connectivity.
Yes, that's why almost no one uses Netflix and Netflix is going out of business.
And that's just talking about today, right now. Give it another 5-10 years, when people are streaming 4k movies in 3D, or whatever the "next big thing" is. Should we wait till then to upgrade our infrastructure? Or just let the ISPs keep running through the same 30 year old lines?
If everyone pre-pays for their next 10 years of broadband bills, I'm sure the ISPs will install the next 10 years of equipment. Other than that, why should they setup anything they don't intend to use in the next year or two?