Re: The official Michael Fassbender / Magneto thread - Part 1
I think the imprisonment is a way of explaining what Magneto has been doing in the time between 1973 and the original trilogy. It justifies why he has not been an active menace in that period.
When we all saw X1, it always appeared that this was Magneto's first major appearance as a villain. But we know from First Class that he has been an active threat for far longer. Periods of imprisonment explain why he wasn't out and about causing mayhem.