Honestly, that's a baffling conclusion to come to, as his parents--in addition to being an actual part of his life and upbringing--clearly provided an environment of luxury, comfort, and engagement beyond measure. I once worked for an elderly Cantonese woman who raised her 3 granddaughters alone, and apparently it's not unusual in eastern cultures for the grandparents to do much of the rising of a child when the work schedules of the parents aren't accommodating. They also grew up with more than a little money, went to expensive schools, and are all perfectly well-adjusted, so there were obviously other factors at play here.
The kid was just off from day one, and no amount of holding, playing, and protecting could possibly have helped. If anything, it'd probably just turn him into an equally entitled momma's boy who would kill his entire family when they eventually paid less attention to him as they lived their own lives. Really, just as no amount of gasoline and body work is going to fix a car with a broken engine, so too would no amount of parental involvement have helped his situation. Lots of folks, rich and poor, have parents who can't always 'be there', and damn near none of them become the unhinged nutjob this lunatic became