Why would they not publish these emails?

Because most of them are completely irrelevant and there is very little informational benefit to warrant this privacy violation. I mean... risotto recipes?

After wikileaks published the material journalists did cover some of it. And even so, they partly regret that, in light of what we know now.

"serious journalists" Approved by the state, perhaps?

Those with a particular "traditional" ethics standard. Which is getting muddier by the day.

It really isn't. You're just becoming more aware of it. There are good journalists, dishonest journalists and everything in between at the Times, which for all its issues is still probably the best newspaper in the world. I'd be a fool to take what they say as fact because they say it as much as they pretend it's so.