I think the problem is more with jobs than with industrial production output. Much of our growth in industrial production has been in items produced almost entirely by machinery: chemicals, construction materials, electric power, etc. The issue is that we're losing a lot of skilled & uskilled manufacturing jobs to China, which IS hurting some sectors of the middle class. I'm not one of these eternal alarmists who've been saying "we're losing our middle class" for the last fourty years (LOL), but manufacturing people have been hurt by China and there hasn't been enough offset to help our middle class from China buying products from our strongest industries: technology, software, and entertainment products.
Don't worry about the %, look at the total $$$ amount.
I think the problem is more with jobs than with industrial production output.
Yes, higher productivity means we make more stuff with fewer workers. You think that's bad?