Thats not quite what happened. His final contact with Scott was a video message telling him he was going to stick around to stop Vulcan and help save the world from that monster's newfound power ruling over the Shi'ar and restore Lilandra to her rightful place on the throne. He told Scott if they fail then he would need to send reinforcements to go after Vulcan. And they did fail in the first mini (Emperor Vulcan). Scott never checked up on him. He never tried to find out what the outcome of the impending war was. The Starjammers were but a small group going against an entire Shi'ar fleet so chances are they would most likely need some assistance. Scott just abandoned them without a second thought. He was called out on it by Piotr got angry but then proceeded to do absolutely nothing. I think he had a moral obligation as his brother to find him, espcially after more than a year had gone by with no contact. It was unnacceptable especially considering the resources he had. He had allies with S.W.O.R.D. that could have been used to hep track them. He had multiple intergallactic teleporters at his disposal, one of the best being Illyana. There really wasnt any excuse for not going after Alex and the rest
Im also surprised Xavier never pursued it. Last time the Shi'ar was left in bad hands was back in New X-men when Cassandra Nova went ballistic and used them to asssault Earth and the X-men. They are lucky Vulcan never did that, but it was still very reasonable that he might have, especially given the hatred he harbored for Xavier. I dont get why this was never treated as an actual potential threat
