I don't think they do have much financial interest in this -- if they cave and give the FBI what they want, Google will cave too (if they haven't already). Regardless of what Apple does in this case, they are going to sell billions of dollars of iPhones.

There may be a few hardcore privacy advocates that buy an iPhone because of this, but it's not going to make any significant change in sales.

And as for criminals, well most of them don't know or care about encryption and aren't thinking far enough ahead about what would happen if the cops seized their phones. The organized "professional" criminals aren't going to rely on device encryption to protect their secrets.

And of course, the cynic in me thinks that Apple (et al) has already given the FBI what they want and this whole case is just public posturing to make the world think that iPhones are immune to government snooping.

Or that Apple's financial interests, moral interests, and the interests of their customers are all in alignment on this issue.

The US Department of Justice has very publicly made that claim, it just fell flat.