They actually did. Remember the Relativity? They talk a big game but, like the regular Prime Directive, the Temporal Prime Directive is secondary to the continued existence of the Federation. That's why there wasn't a peep out of them when Kirk stole some whales from the past.

The temporal accords were meant to protect the timeline that lead to the temporal accords and that includes any alternations to the timeline up to that point. All of them.

This was the true cause of the Kelvin timeline.

Would you try to stop Janeway? Yeah, I thought not.

It's the Sacred Timeline!