I agree with you. They're not altruistic at all and the FBI thing was likely a PR campaign. They already have a number of behaviors that hurt users, app developers, and people in the supply chain. Far as security, the hardware engineers know there were attacks all the way through the stack that can be mitigated with certain tech that would probably cost them a few million or tens of million one-time development. They used a weak, 3rd-party approach instead. They never brought up these weaknesses, which all commercial smartphones have, during the debate. They still don't.
So, let's recap. Tim Cook, already hit due to privacy issue, might have a personal stake in improving privacy in tech. They knew their products weren't secure. I knew third parties that could've cracked it as they cracked IC's designed for security w/ obfuscation & tamper-resistance. As I predicted, the FBI ended up finding a group that cracked it for a low, six digits. That means the attack was easy with much of that probably profit.
That Apple knowingly leaves their devices insecure despite having money and incentive to knock out low-hanging fruit means all this talk is mostly branding. They're just differentiating themselves with appearance of greater security/privacy. Like they did when they said Mac's were immune to malware back in the day. Except this time, they actually deliver a good chunk of what they claim at least. I'll give them that. :)