I find it hard to believe something is unusable for an issue that it seems like the majority of people you know don't even notice the problem.
Indeed. The hyperbole with which these kinds of claims are made is what makes them so hard to take seriously. I'm constantly reading on these boards about how iOS x.x will absolutely cripple any device that's more than a month old. At present, I'm running 9.2 on an iPhone 4s, an iPad Mini and an iPod Touch 5g. All of them are working just fine.
I'm guessing I just have a different idea of what constitutes "usable" than some folks. If I'm using it, it's usable.