Former senior product manager for Apple's security and privacy division Window Snyder agrees. "If someone attempts to force them to work on something that's outside their personal values, they can expect to find a position that's a better fit somewhere else."
In another instance of Apple's company culture clashing with what the federal government demands, the development teams are apparently relatively siloed off from one another. It isn't until a product gets closer to release that disparate teams like hardware and software engineers come together for finalizing a given gizmo. NYT notes that the team of six to 10 engineers needed to develop the back door doesn't currently exist and that forcing any sort of collaboration would be incredibly difficult, again, due to how Apple works internally.
It sounds like that would be a ways off, though. Apple is expected to exhaust its legal options before relenting to Uncle Sam's pressures to crack the device open. Another option that could be pretty far-fetched would be if every Cupertino engineer capable of writing code quit their jobs. That'd show that Apple was trying to comply with the federal request, but it wouldn't have to follow through because it wasn't possible to do so.
The most realistic situation on the government's part? Probably something similar to what the it did with Lavabit
during the Edward Snowden kerfuffle: daily $10,000 penalties until the company complied. Rather than doing that, though, it shut down instead. Whether or not Apple, one of the biggest companies in the world, will follow suit remains to be seen.