One of the first strategies I implemented when I joined here was writing on a variety of topics to gauge their overall performance with traffic and earnings.
Those home improvement hubs are actually the poorest performers currently of any of my topics in traffic and earnings. I credit it to them being pretty uninteresting and lacking any personality. They're based around keywords, but they don't seem to be indexed yet, so it's possible that in the future traffic might pick up.
I don't expect to be focusing in that direction anymore myself, but that's not to say it can't be profitable. For the most part, I think people running other online businesses have an interest in HubPages for the backlinks it can provide.
I've found that the community structure of the site here acts as a good motivational tool for me to write when I otherwise wouldn't, so that's why I'm interested in the platform. I don't see any reason why you couldn't focus on a specific niche and build regular hubs to both provide backlinks and income potential from the hubs themselves. I can see that working.