King Daniel wrote:
Look at what Daniels' attempt to protect Archer caused in "Shockwave" or Braxton's attempt to fix history in "Future's End". Look what happened after "Endgame" in the novelverse.
Say Spock warns Starfleet about the Borg. Starfleet investigates a century earlier than the Hansons' did in the Prime universe and try something Kirk-like and reckless which brings the collective down on an unprepared Federation. Say he warns them about the Bajoran wormhole, which leads to an earlier Federation/Cardassian war. Say he warns Deneva about the parasites, and a century later a survivor's child starts experimenting with the omega and renders the entire alpha quadrant impassable to warp ships.
I'm not saying Spock 100% shouldn't interfere, but I can see why he may choose not to.
I'd think of it as a matter of risk. You've described risky scenarios where the payoff could be either great good or disaster on a galactic scale. So yes, it's probably not good to interfere, here.
Now if V-ger shows up at Earth's doorstep, or the whale probe does, and the threat is immediate and time is short, I could see Spock Prime saying, "I may be of some assistance, here."
Spock Prime could be like a firefighter helping put out fires when the occur, rather than the cop on the beat, trying to prevent or deter things from happening.