Because DNSSEC can't be trusted. Instead of placing the trust on the commercial CAs that have all the incentive to do a good and trustworthy job if they want to stay in business, DNSSEC places trust on the various countries registries that have all the incentive to abuse their powers for national security or to enforce the current governments beliefs.
Of the two evils, the CA model is slightly better because the incentives align
> [...]Instead of placing the trust on the commercial CAs that have all the incentive to do a good and trustworthy job if they want to stay in business, DNSSEC places trust on the various countries registries that have all the incentive to abuse their powers for national security or to enforce the current governments beliefs.
With very high probability, there are a number of nation-state governments controlling some entries in your CA store. Even a short glance at the content of debian's "ca-certificates" package gives these:
- CNNIC (China)
- TÜBITAK (Turkey)
- WoSign (two certs, one specially named for China)
- Juur (Estonia)
- TeliaSonera (Sweden, Finland)
The last two are likely not going to be compelled to issue rogue certs, but technically the data interception laws in Sweden (and the ones proposed in Finland) might not even require any modifications to allow such operations. There are probably a lot more.
Certificate pinning will help, but even that faces a bootstrap problem for new clients. With smartphones being replaced, on average, every two years, there are ALWAYS new clients. Incidentally, a wide-scale MITM for new clients only is something I would expect the Great Firewall to be capable of.
So the commercial incentives for CAs may be more suitably aligned, but there is still overlap with the DNSSEC problems.
If only the registrar holding a domain can issue certs, and for example you don't trust CNNIC or the .cn TLD operator (which also happens to be CNNIC in this case), then you can simply avoid .cn domains and register your domain elsewhere, at a registrar that you trust not to issue fake certificates.
If you cannot trust the TLD operator, then you have already lost, as the TLD operator could arbitrarily fake data in WHOIS if only for a second, and obtain a DV certificate from any CA right now, since a WHOIS lookup for an email address is usually what powers the DV. But at least then you'd eliminate the risk of third parties (not the TLD operators) obtaining a parallel certificate that you don't even know about. Right now, I don't think there's anything stopping CNNIC (or any other root CA) from issuing certs for yourdomain.com, and you wouldn't even know it.
Might bring some value back into the reputation of TLDs and registrars, as a bonus :)
> DNSSEC places trust on the various countries registries
I'm not a security expert. Aren't DV certificates put trust on the registries too? If you control the domain then it's trivial to get a DV cert for the site. So with the CA model you trust both CAs and registries.