Originally Posted by Yagami Crewman
The Borg are coming and have been since a signal was sent in the 22nd century. Q just gave Picard a cold water wake up to this fact. Nothing Nero has done would change that. Nero's weapons won't stop V'ger or its quest to find "The Creator"
Praxis exploded due to over mining. Nero doesn't care so HE won't tell the Klingons to be enviromentally minded. (Even if the warning would be heeded.) There is no reason for the Klingons to change their mining practices unless Spock Prime warns them and the very act of warning them might fall afoul of the law of unintended consequences.
On the other hand it might turn out better... The events on Praxis are very much susceptible to change.
Look at it like this: Let's say that Character X lost his parents in a car crash. He goes back in time and prevents the accident. The lives of himself and his siblings will immediately diverge from the original path, but the life of someone the same age on the other side of the world may not be affected by the Butterfly Effect for many years or maybe not at all.
I see what you're saying but maybe in this timeline the borg never got the signal. Or there are no borg, they were wiped out by another species. Maybe the Klingons updated their mining practices or they used Praxis for something else or never even used it at all? There could be an infinite number of alternate realities, or universes existing next to our own time and they might all have a different progression.