Again, you're misremembering the episode. Here's the transcript.
There was nothing about any kind of noninterference policy here. There was no effort to hide the Novans' origins from them; on the contrary, this was a story about reintroducing the descendants of a lost colony to their true identity and heritage as humans. They brought a sick Novan up to the ship to cure her of a terminal disease, reminding her of her real name and the names of her parents in the process. And they rescued the Novans from the radiation sickness that was killing them, transplanting them (presumably using several dozen shuttlepod trips) to a new land mass free of radioactive contamination. They absolutely did
do everything they could to help those people. And it stands to reason that Earth would've sent more aid to the Novans after they got Enterprise
I think you need to rewatch Enterprise
before you start any more threads evaluating its moral issues.