The Alphans fight the Wrecking Crew, who are being manipulated by a skillful Canadian politician who is trying to gin up support fo a superhuman registration act. Hence the Terminator-like robots.
Because that plotline wasn’t already overused in the U.S.-based storylines. And because it allows for such dramatic splashpages as this:
Creators: Simon Furman and Pat Broderick
Grade: D-. It’s not an “F” because I always enjoy the Wrecking Crew.
For the complete history of the MU, year by year, go here.