I don't avoid the granny gear. It kind of depends on the ride, though. I've had to use it for smaller hills I usually do in the middle ring on my Kuota, so as not to aggravate my back. Climbing does do that. I also have a 12-28 on the rear. I have a compact with mountain gearing on the back on my Guru, so if I'm in the small ring, who cares? I have to change gears a lot more on the compact, while I can be mostly in the middle on my Kuota. But, I do live in a hilly area.
Today I used the Kuota for my metric ride to celebrate my birthday. We were in towns I rarely ride in, and did lots of neighborhood hills, some up to 5-8% grades. My back started in at about 20 miles, but, it was nothing horrible. After I stretched, it's fine.