Hope you did notice the smile after my comment But there obviously was a bit of truth to it. As opposed to say 20 years ago, the open source community gained an enormous momentum. Back in the day almost everything was closed source. And now even programs from browsers to entire IDEs like Visual Studio Code are all open sourced. I’ve seen entire game engines turn open source, whereas this was never possible in the old days where everyone wanted to keep everything for himself, forcing everyone else to reinvent the wheel over and over again.
Keeping everything closed, can be less secure, more error prone and also has the risk that the development is slow. If some manager decides that a dev team can better used somewhere else, the end-user will bite the dust, as he will never get any new updates or they will be delivered excruciatingly slow.
In my opinion, making it open source has a huge potential in generating more customers if you have an entire dedicated community focused on making the best DJ tool out there, not just a small team at Denon.
Sure, I understand that company secrets probably need to stay that way. But a lot of other things could be opened up. At least through some SDK, as some mentioned here as well.