People leave their jobs for all kinds of reasons, especially when they are offered exciting new jobs at important, on-the-rise companies.
However, someone in Lattner's circle of developer friends shared some insight with Yahoo! Finance at to why Lattner was calling it quits at Apple now, even as one of his major contributions, Swift, had really taken off.
This person said one big reason was that Apple's culture of secrecy was wearing on him, particularly because it was his job (and his life's work) to create open-source developer tools.
"He always felt constrained at Apple in terms of what he could discuss publicly — resorting to off-the-record chats, surprise presentations, and the like," the person told Yahoo! Finance. "Similarly, I know he was constrained in recruiting and other areas. Eventually I know that can really wear people down."
This wouldn't be Apple's first time losing someone in a big public way because it insists on secrecy over collaboration. As previously reported in several sites, Apple's entire networking team quit within a one-week period back in 2015 when Apple asked the team to build a bulletproof network and then refused to allow it to collaborate with others outside the company in its field doing similar work via an organization called Open Compute Project. (OCP is led by Facebook.)
The Apple networking team then took the networking tech it built at Apple, based on open-source software, and launched its own startup called SnapRoute, which has since taken the network world by storm. After its members quit, Apple relented and officially joined the OCP.
Apple was also forced to change its policy of secrecy for its artificial-intelligence team. In December it allowed that team's members to start publishing research papers on their work and otherwise collaborate with academia. Just a few weeks ago, the Apple AI team published its first paper.
That was a major reversal, and it came because Apple's tight-lipped approach was widely thought to be hindering its ability to hire the best people in the field of AI. AI is the biggest trend in the tech industry these days, and those creating new ways for computers to learn and to reason want to show off their own accomplishments to the greater AI community.