It wasn't about energy use, simply that to pay their rising electricity bill they will be looking to save money elsewhere, and broadband tends to be one place people do not see the value in higher cost services.
Few people understand what contention is or that the issues they are having with broadband might be they are paying for too slow a package. Just as there are plenty of people who don't understand the problems they are having might be WiFi related rather than their broadband service.
Its not all that surprising, its not like budget ISPs go out telling people "we have twice the contention of more expensive ISPs", nor would the average person even know what that means.

I think most people probably think an ISP is like their energy company. Its all coming from the same place, they're just being billed by a different company. I don't really blame them, its hard to get your head around just how complex broadband delivery is when you ARE the kind of person who is interested in how it works.