I'm pretty sure the main motivation was Marvel trying to portray him as wrong during the era, hence "Cyclops was right". It also picked up after AvX...
Personally, I saw that moment as Magneto sucking the air out of the room from Xavier and laying the seeds to be placed at a spot as close to the top...
He was also charged up by Storm once, forgetting the issue at the moment. Pretty sure it was by Claremont. I don't think it made his beams stronger,...