"Nor would I ask you to... I am merely asking you to make friends. I trust your judgment as to who you make your friends."
If Magneto was the force that turned the earth to a new day, then Xavier was the sun. He wasn't as bad as most of his brotherhood members had created him to be... Xavier and himself were two sides of the same coin. There was a part of him that even wish for his long friend to be with him here today... however he saw the necessity of his departure.
The world had turned into the night, as no day could last forever. The golden age of Xavier has passed. Magnus now had to herald the incoming night that would once again pass to bring a new sun. A new golden age was on the horizon. Magneto only had to find it.