Well, those aren't entirely separate things. In the instant case, Apple is being asked to create a tool to open an existing phone. That clearly falls under the umbrella of "hacking a phone".
If they were to continue selling phones (that is, after all, what they do) after creating the tool, though, they'd be intentionally shipping phones with a known vulnerability[1]. So it's perfectly sensible to describe the request as being "to create a back door".
[1] I am given to understand that the phones Apple currently manufactures would not be vulnerable to the tool they're being asked to create. I don't feel that changes the issues I mention, but it does mean they don't apply perfectly to this case.
Also, I'm not sure newer phones are unaffected, here's a line from Apple's public letter:
>Specifically, the FBI wants us to make a new version of the iPhone operating system, circumventing several important security features, and install it on an iPhone recovered during the investigation. In the wrong hands, this software — which does not exist today — would have the potential to unlock any iPhone in someone’s physical possession.
Emphasis on "any iPhone".
These are all great arguments for Congress to consider. Maybe there's a good reason to create a privilege, like doctor-patient privilege, for companies in Apple's position. As I think you acknowledge, this is a political judgment that must be made by the people's elected representatives. As an aside, you're playing the same game with the definition of backdoor that we were accusing the government of before. Hacking a phone is not creating a backdoor. Shipping phones with an intentional vulnerability is a backdoor.
>But even then as baldajan pointed out the first amendment issues are way more than just code. They are also about the core values of the company. Apple should be able to choose what kind of dent they put in the universe.
So let's assume that Apple outright had the PIN in their possession. They would be forced to hand it over. "What kind dent they want to put in the universe" notwithstanding. Again, you're asking the court to come to a political decision, not to interpret the law as it exists and has been applied repeatedly to other cases.
The court is not the third house of Congress.