That would then make you chips more expensive than the competition and less competitive on the BOM side, and BOM costs are a different accounting budget than SW licenses.
People in the industry have already thought of this. HN likes to think they somehow found the magic solution nobody ever has thought before, when the truth is HN doesn't understand sales of the HW industry.
Besides, "ignorant" HN comments on e.g. FOSS software and funding problems have mentioned that the paperwork you have to do to buy software licences can be a PITA, so free software can be perceived as a plus when the R&D selects the parts.
People have already thought of that, sure. But has it been thought about and executed properly? Like the added value of open-sourcing the SW (made a lot easier when you don't need to copy-protect it). Or do they just go for the extra source of profit the SW licence sales provides, anyway?
The company I worked for was selling million or tens of million of units per year. So in such cases it's easy to see why BOM costs trump the SW costs of a few licences, and why HW companies would like to keep chips costs down and charging you per SW license.
If you haven't shipped million of products in embedded and only worked in SW development, it's easy to get a warped picture of reality.