It's a little tricky to explain why this is the case without getting into a lot of gritty detail. A shorthand answer is that browser vendors have, pretty much as a group, decided not to adopt DANE (the DNSSEC-based alternative to the X.509 CA system), and DANE is the only reason anyone cares about DNS security on an Internet where everything is going to be encrypted (usually with TLS) by default.
You don't need a secure DNS for the web.
You don't, with STS deployed, need a secure DNS for email.
Is publishing SSH key fingerprints so important that we should do a forklift upgrade of the DNS? No, of course not.
Also, I think you're underestimating the growth of DNSSEC deployments. I've been watching DNSSEC growth for about 2 years and it is steadily moving up and to the right.
It is nowhere near ready for universal deployment today, and, indeed, virtually nobody relies on it, unlike TLS.
I guess I don't have some expectation that deployment should take place quickly. Or that the first go at a protocol is going to always get it right. Just because a journey is difficult doesn't mean the journey isn't worth taking.
DNSSEC and TLS are unrelated. They're trying to solve different problems.
Geoff Huston at APNIC does some good work at measuring validation. Check out slide 2 and 24 of this preso. https://meetings.icann.org/en/marrakech55/schedule/wed-dnsse...
Again, I'm not arguing that DNSSEC adoption has been easy and fast. But it's being adopted steadily.
In the current protocol the only difference between offline and online signing is in how authoritative servers are implemented. There the differences aren't all that significant (relative to building an authoritative server as a whole) -- the same data needs signing, etc -- so please explain how your protocol makes implementation simpler.
> Obviously it would not be the only difference.
Can you please expand on that? You've said you've been thinking of a DNSSEC2 proposal for a while so you must have more to say.