I say that Future Guy was a Section 31 agent who got access to time travel technology and took pre-emptive action to an extreme in his effort to negate threats to the Federation.
He tried to start a civil War in the Klingon Empire. Maybe the Klingons would eventually threaten the Federation. (Or maybe Future Guy was originally from Kirk's day and couldn't shake his prejudices.)
He gave Archer crucial information about fighting the Xindi, who were threatening to destroy the Earth.
The worst thing he does to the Enterprise crew is frame them for the destruction of Paraagan II. But who knows? Maybe the point was not to frame Enterprise, but to destroy the mining colony. Maybe the Paraaganians would become a big threat to the Federation in the future, or whatever they were mining would someday have been used in a devastating weapon against the Federation.
Enterprise relaunch authors, you heard it here first!