These things can be completely irrational in my experience. One part I was working with had a driver upstreamed in the Linux kernel, you could buy off-the-shelf

These things can be completely irrational in my experience. One part I was working with had a driver upstreamed in the Linux kernel, you could buy off-the-shelf devices for cheap that had it on the PCB and I even found a company that was apparently selling a complete set of layer-by-layer die shots of that part for around $1000. Yet the chips weren't sold by any distributor. To even just get engineering samples from the manufacturer you had to sign this draconian NDA that covered everything from software to hardware docs even remotely connected to their part. Even after signing the NDA they wouldn't disclose full datasheet for e.g. what some registers did. For some things the comments in the Linux kernel turned out to be more informative than anything we got through official channels. But if they're the only source of parts you have to use, you have to dance by their rules. Ruin the relationship by breaching the NDA and you might just as well bury the product you spent a year developing.