What do you mean "do much"? Wouldn't negatively impact users, or wouldn't help the botnet problem?

The article makes it sound like the issue is largely compromised routers and cameras -- and presumably cameras are less likely to be publicly-accessible to get compromised in the first place.

ISPs are able to update firmware on the routers they own, so it's my guess that it's customer-owned routers that are the main issue here.