Fundamentally, because unlike driving our right to bear arms is enshrined in the 2nd of our 10 foundational constitutional amendments, and licensing, registrati

Fundamentally, because unlike driving our right to bear arms is enshrined in the 2nd of our 10 foundational constitutional amendments, and licensing, registration, etc. are historically used to disenfranchise certain groups in favor of others. See: voter ID debate. We make IDs required and "all you have to do" is go to the DMV that's only open during hours you work, has absurdly long wait times, and we close down the ones near predominantly black neighborhoods. The same would certainly happen for the kinds of firearm regulation you propose. Which isn't to say there isn't some reasonable compromise to be had there, just that there is a pretty reasonable argument why we don't do that.