Because the world is changing and it's no longer socially acceptable to just pay what's legal, it's considered inappropriate to pay less than what people would consider to be a fair amount. If you're paying $1 of tax on $1000 of earnings because you've cleverly nested your business assets overseas in a complex web of tax avoidance schemes, then most people would consider that unfair, even if it is legal.
I'm curious; how do you define "fair", and how would you go about forcing companies to "be fair" when they are not? Think about it for a bit. I think you'll find that's exactly what the law is intended to be, of which ( I'm guessing ) Apple is not in violation of. Our government setup this game, and now it is mad that someone dare play by the rules. Doesn't that seem hypocritical to you?
The problem isn't companies like apple. There will always been companies like Apple. They are a symptom of the underlying problem; government doesn't know how to make tax law.