Another thing about Janeway's statement is something I found on all three next generation set shows. They seem insufferably self righteous and self important in their attitudes. They look down on 20th century culture whenever it's mentioned, at least it's consistent that she would look down on 23rd century events as well.
I think Captain Kirk seemed to be concerned with the Prime Directive, but he didn't feel enslaved by it. It seemed to be a rule that said don't ruin the lives of people he met. If he thought their lives were already bad, then he acted against what the 24th century strict intrepretation would later be, but not against his own interpretation.
Landru had to be eliminated, the people were in a weird stagnant culture. Vaal, too.
No one was too interested in the Prime Directive when the Klingons moved on Organia.
The Providers on Triskelion weren't really doing too much for their people and Kirk tried to better the situation, plus I'm not sure if they would even fall under the PD.
The Omega Glory had clear violation of the PD, by Cpt. Tracey, not Kirk.
Kirk and crew tried to avoid all contact with Miramanee's people in Paradise Syndrome, but they were there in the people's best interest, deflecting the asteroid. In the clenched anus 24th century, the PD would say the best thing to do is let the asteroid kill them all.
When did Kirk really violate the PD? Maybe with Vaal and Landru, but that's a maybe.