Cars are not built only for public roads.
https://www.mazdamotorsports.com/2019/02/07/a-better-faster-...
And Spec Miata is a pretty terrible example anyways... at the point where you're dumping 10k into a $500 motor I don't think you can talk about stock anything...
We should empower people, not manipulate them through engineering usecases to/to not accommodate.