Earlier quoted context omitted.
Single word answer: trust. Y’all seem like nice people but trust isn’t automatic these days.
Trust with regards to...? Orion doesn't have any telemetry, doesn't force any updates on you, doesn't require any account. You can audit the application's behavior with standard tools to verify that it isn't "phoning home", etc., it doesn't need to be open source to do that, nor would making it open source obviate auditig the final executable anyways. What do you perceive as the risk to "trusting" Orion in this case?…
I think a blog post on Orion's transparency is enough. The fact that there is Orion+ is enough to warrant no need to have tracking or 'enshittification'.
If you like Kagi and Orion, supporting development by paying for it makes sense.
Open sourcing everything of Orion means that Orion+ will be open source which defeats the point of supporting development of Orion directly.
I've seen projects start open source, change to closed source and then add in the enshittification later. It doesn't matter if the code is 'open' the source code would eventually be unmaintained and have security holes which there is no time in the world for anyone else to maintain.