Except those $2.50 for customer will turn into $2500000.00 for the hardware vendor. And they would rather keep the $2500000.00 and let it be someone else's problem.

If you're shipping 1 million units, don't use Linux. Done.

You are implying hardware vendor is the one who got to choose the OS, but that's often not how it works.

Who's forcing it on them? Or, are they systemically incapable of evaluating what their suppliers are providing? Sounds defeatist to me.

Spending hundreds of thousands of dollars in additional bulk cost for the privilege of nothing other than adding systemd to the device, what a steal!

$2.50??