I think it means dismantling one phone requires Apple's assistance , but forcing them to give the FBI the "key" would allow them a much broader approach to violating the rights of Americans , potentially without judicial , and public oversight. If they get Apple's disassembler language they can use it at will , without bothering to get a messy , slow , warrant. A while back , TrueCrypt was used to lock a laptop the DOJ wanted access to , and asked the court to demand the suspect give up her password. The courts eventually decided (and rightly so , IMO) that possession of the laptop was an evidence issue , rightly obtained through warrant , but the password was a 5th Amendment issue , and therefore the court could not compel the accused to reveal it. The DOJ never got in to the laptop. The US government couldn't crack the encryption , claiming they could, but it may take a few thousand years.
Apple can do it at the hardware level , because it's their encryption. For the FBI to do it would require them to have the necessary software-which would then give them the keys to the kingdom.. Some have disagreed with me , but I don't believe the government has an inherent right to be able to snoop in to anybody's business they get a whim to. If they have the ability they will use , therefore misuse , it. Anybody who thinks our government can be trusted , take a look at our current election cycle. The power structure of a candidate's own party is trying to subvert , and derail , his candidacy. This , in obvious opposition to the will of the electorate. They don't want anyone who isn't in their network near the real reins of power. They don't care what the people want , it's all about power. The Apple case is about that same government wanting more power. How much faith in their "good intentions" can we really have?