To me, it's absolutely nuts they don't have entry paths to their crown jewels. What will IBM's competitive advantage if everyone migrates from AIX and IBMi to Linux? While there is no IBMi emulator, there are commercial environments that can compile and run COBOL and PL/1 code made for i on x86 Linux machines.
There's no way z/OS is going to be free or open-source (if for no other reason than if they open sourced it, you'd still need a mainframe, which means you're going to pay IBM for cloud time), so if hobbyists are going to start with something they'll probably start with Linux. Once they are no longer a hobbyist, IBM will be there to help.
This is probably why IBM mainframe OSes until the 1980s are public domain: You can't run MVS without an IBM mainframe, so why bother even copyrighting the source code? The Hercules people are grateful for that bit of pragmatism.
http://www.hercules-390.org/hercfaq.html
I never said that.
What I said is that there aren't any onboarding routes to z/OS (or AIX, or IBMi). You either already are running one or more z/OS boxes, or you'll just deploy to cloud, CentOS, Kubernetes, OpenShift, on commodity CPUs (x86 and ARM), or any of the other stack that rivals a mainframe in some capabilities (and carefully avoid business requirements only a mainframe can fulfill)
Not sure if big-blue ever had that kind of person in abundance to be honest. Was recently reading up on the DEHOMAG thing recently, and well probably not. At least Watson tried to give the Nazi medal back, haha.