In a word, the kid was cute. . . not just physically attractive "boy next door" type of cute, but he had the personality that resonated with the audience (especially girls) and the judges. He didn't act precocious but gave respect to the judges.
The other side of the coin is that he's a Poor Little Rich Kid (PLRK) and my problem with such kids is that they can afford the top end toys that most cannot. I'm not just talking about a couple of the prediction pieces he did that sell of a few thousand bucks, but the grooming and training he's seen, the political clout of his family, etc. It is much easier for a kid to progress when mum & dad belong to the "right" country clubs, if you get my drift. Of course ties of this sort are usually obfuscated by one's Press Agent and the sad tale of a struggle put in its place, but the truth is the truth and political connections trump talent every time.
a joke in Hollywood when I lived their 35 years ago was the easiest path to success meant you had to be Gay, Rich, Available (sexually) or Jewish if you could fill 3 of the 4 niches you had it made. . . the more slots you could fill the better. But notice how "Talented" isn't on that list. . . that's because even way back then talent wasn't the primary key, producers knew that they could get acting coaches, etc. to help "tune" a prospect and get them ready for the job, most of the time their investment would pay off but then there are those horrid exceptions, most of them easily defined by the terms SLUTS or GOLD DIGGERS with a Daddy (or Mommy in some cases. . . like the Comedy Club).
Colin, if I recall corectly, was a Castle Jr. member which also gave him his own level of political favor, especially if he was one of the chosen favorites. . . many of today's top names were Castle Jr.s or part of the Long Beach Mystics; it's not a coincidence.
Hope this fills in some of the blanks.