Ada only caters to developers and industries that care about quality before price, and where sloppy programming and cutting corners might kill people.
Given that the computer industry still enjoys EULAs with disclaimers, product refunds and lawsuits due to sloppy programming or CVE exploits are still pretty rare, it is almost impossible to convince people otherwise.
One of the great outcomes of the increase in malware attacks is finally getting more buy-in for safer native languages.
