The issue went up to the producers, hence his quote about people "schmoozing at cocktail parties" while people on set were treated poorly.
Eccleston has repeatedly said that The Empty Child 2-parter was the best script he was given though so maybe he'd be up for returning if Moffat was behind it. Doubtful but weirder things have happened.
The cocktail parties line was in reference to the difference between acting for adults and children - it's not clearly a reference to the conditions on Who at all so you're making a big assumption there. No one else seems to have had an issue with the amount of work that Collinson or RTD did.
Yeah, that quote seems to be more about his audience: children vs. television critics: "It was a great part. I loved playing him. I loved connecting with that audience. Because I’ve always acted for adults and then suddenly you’re acting for children, who are far more tasteful; they will not be bullshitted. It’s either good, or it’s bad. They don’t schmooze at after-show parties, with cocktails."
That said, even though Eccleston liked working with Davies before, I'd bet the working environment of Doctor Who was very different from The Second Coming.
Sorry, but the snippet you chose was very out-of-context when the whole quote is put together. Yes, he loved working for children and yes, he loved playing the Doctor for a generation of kids, but the cocktail parties thing is NOT a general statement about working for adults (why would it?? most adults don't attend cocktail parties regularly), but a callback to him specifically complaining about the media culture of those who ran the show.
Here it is:
Christopher Eccleston said:I left Doctor Who because I could not get along with the senior people. I left because of politics. I did not see eye-to-eye with them. I didn’t agree with the way things were being run. I didn’t like the culture that had grown up around the series. So I left, I felt, over a principle. I thought to remain, which would have made me a lot of money and given me huge visibility, the price I would have had to pay was to eat a lot of shit. I’m not being funny about that. I didn’t want to do that and it comes to the art of it, in a way. I feel that if you run your career and.. we are vulnerable as actors and we are constantly humiliating ourselves auditioning. But if you allow that to go on, on a grand scale you will lose whatever it is about you and it will be present in your work. If you allow your desire to be successful and visible and financially secure – if you allow that to make you throw shades on your parents, on your upbringing, then you’re knackered. You’ve got to keep something back, for yourself, because it’ll be present in your work. My face didn’t fit and I’m sure they were glad to see the back of me. The important thing is that I succeeded. It was a great part. I loved playing him. I loved connecting with that audience. Because I’ve always acted for adults and then suddenly you’re acting for children, who are far more tasteful; they will not be bullshitted. It’s either good, or it’s bad. They don’t schmooze at after-show parties, with cocktails.