Risk aversion.
Shareholders don't like lawsuits. They don't like it when their baby is insulted or blamed for things beyond its control. So they instruct their board of directors to be risk-averse. Extremely risk-averse.
Pretty much anything could be offensive to *somebody*, so Apple's employees are told to play it as safe as possible. What Apple are doing is a symptom of the lawyer-happy society their HQ is based in. ("When in doubt, sue. Even when not in doubt, sue anyway as they might settle out of court just to shut you up." Either way, the lawyers win.)
And in case you think it's only Apple doing this, I suggest you pay closer attention to the news. (And no, it's not just the US either. The UK -- to pick just one EU member nation -- has become infamous as the capital of "libel tourism".)
Stop blaming the corporations. They're obliged to follow exactly the same damned, bat's-arse laws as you and I. The difference is that they're much bigger, wealthier targets and thus far more likely to get sued for money.