After already losing Rosalina to who knows where and his son princess who knows what, losing Peach is galaxy than the kind hearted Mario can take and he hangs himself in his Mansion to be with the woman he loves and his childen peach thinks are Super gone too……Which explains why Luigi is trapped in the Manson.
Princess Peach [Super Mario Galaxy]
Peach is both left and right handed while Luigi is left handed. Having her entire kingdom turn into blocks is not a good look for any ruler.
Super Mario Galaxy 2 (Video Game ) - IMDb
He may end up saving Peach, but he inadvertently caused harm to the citizens of the Mushroom Kingdom.
Princess Peach - Wikipedia
Super Mario: The Worst Things That Have Ever Happened To Princess Peach