You would use it if you wanted to get a job doing RTOS dev and wanted to show you had some skin in the game.
lmao "skin in the game". what a useless cliche.
that's such a lame excuse, and if for some stupid reason, i chose the rtos first, i would simply choose one of the many competitors that have positive mindshare and increasing install base. freertos, rt linux, hell even vxworks.
the simple fact is that rtos are more commodity than ever. if im going to start a project, im going to do it based on the requirements, find a soc and bsp that has excellent support for those requirements, and then follow up writing a task for whatever rtos it uses.
for example, im not using freertos because its "cute" and has a neat little floppy disk demo. im currently using amazon's freertos beceause that's what the espxx family supports. im using the esp32 because it has the power profile i need for my sensor project.
in today's market, it's absolutely asinine to choose the rtos first. i honestly have no idea what qnx is a first class citizen on anymore. I actually feel bad for anyone who's spent their whole career in QNX-land - that train might be coming to a stop and there's probably a lot of people who would rather not retrain.
actually, there's a nugget of wisdom in there for the qnx team: i should be able to buy a $20 board that runs qnx, and fits into the power, performance, and hardware profile of something like the esp32. integrate it heavily with platform.io. let me use qnx without having to specifically go and seek it out and hack on it a bunch.
any commercial rtos shop where QNX may be appropriate is either using 1. some wacky expensive proprietary rtos that you've never heard of, 2. freertos or 3. real-time linux depending on what they need. asking what makes QNX a compelling rtos when freertos exists, is widely supported and used, and has an MIT license is a very valid question.
further, no one in embedded actually cares what RTOS you used. they are all similar enough that you won't get stuck if it's a brand new RTOS
I don't think that "skin in the game" means what you think it means.
Maybe you would have used QNX as an engineer flex in 2012, but as an embedded firmware dev myself, I'd laugh if someone suggested we use QNX for anything. Besides the licensing issues... just why? It confers no imaginable benefit versus any one of dozens of alternatives. It's like if someone suggested I run Haiku on my work laptop.