How many of these horses are coming back at this level fresh off or with in one start of a maiden win?
I'm no expert by a longshot, but I would take a guess that in this scenerio (3yo's in January) the horse broke it's maiden against fairly weak company, and rather than run in conditions where the trainer (and this is where it's imperative to have one with a great evaluative eye) is confident that the horse will be outclassed in NW1x company, they opt for AOC where they may get more intrinsic value fresh off the maiden win.
If for instance you have a horse that say, runs a 60 beyer avg over 3-4 starts, then breaks maiden with a high 60's effort, the horse has added value to himself by winning with a career top. Now as an owner you need to try and evaluate whether he's coming into a different level of form, or he just had a great day...Now say you paid 40k for the horse at a 2yo sale, and you can run him next out in a NW1x AOC with a 75K tag, he would probably one of the better runners in that field, although most likely would not get claimed first out at that level.
So you get the opportunity to run for Allowance type money, against little lower class of horse, a better shot to get your picture taken, and if the horse does get claimed, you probably made out - you'll get almost double what you paid.
The issue get more muddy and less appealing in state bred company, which is why you see more of these races written for (3yo's) in open company in the winter, especially in NY and FL.
Don't know if this makes sense, but that's my wild assed guess
