In other words, they're trying not so much to stop comparing apples to oranges, as to find the commonalities between apples and oranges and to judge those objectively.
One of the most common parent conversations at skating practices goes like this:
Parent A: I see Mary has her double lutz.In other words, we're looking at all those apples and attributing their success to the fact that some of them are actually oranges.
Parent B: Yes, but look at those legs. Of course she's landing that jump, whoever saw thighs like that on an 8 year old.
Parent C: Her folks can afford four lessons a week, too. If I had that kind of money, Johnny would have his lutz and then some.
Lots of factors go into success as a skater. You can't really compare them, which was the point of IJS-- ranking skaters to choose a winner was inherently unfair. How in the world do you compare Michelle Kwan and Surya Bonaly, two brilliant skaters with nothing but the framework in common.
But compare them we will. We'll go ahead and ascribe positive motivations to the people that came up with the IJS, and try to figure out how to compare our own apples and oranges, from the stands, without the catty comments (okay, maybe a few catty comments).
Age
Age is less a factor than you might think in actual skating ability, as anyone knows who's watched the little 6 year old dynamos who keep crushing your talented 9 year old at Regionals. It's better, both for your own ego and as an objective factor, to consider a skater's maturity. A 9-year-old who cannot focus on a lesson or direct her own practice is going to be less successful than a 7-year-old who can.
Body Type
Not a factor, unless your body type is "40 pounds overweight." There are certainly some physiognomies that help a skater-- flat bosom, long waist, bow legs-- but we've all seen enough body types to understand that there is no body type that actually precludes skating success. Body type complaints and kudos (think Rachael Flatt and her supposed problems because of "sloping shoulders," or the positive but frankly racist assertions about Asian body types) are about aesthetics, not athletics.
Trajectory
A kid who is not aiming for Nationals is not going to Nationals. I don't care how talented he is. To achieve a goal you have to set it. No one gets into elite skating by accident. You can't compare your recreational skater, who likes to try new stuff, to the 30-hour-a-week phenom.
Motivation
Motivation pretty much equals Maturity + Trajectory. You have to know your goal (elite skating, International competition, Gold level tests, a certain jump, a solo in the ice show, or whatever), and then manage the steps it takes to get there. Without motivation, the game is over. And mom can't supply it. Further, motivation doesn't just mean "motivated to win competitions." Kids are motivated by, and toward, different outcomes. Don't compare a kid who's motivated to win Nationals with one who's motivated to landing the axel before graduating high school. Both are worthy goals; comparing them is pointless.
Coach
Even given talent, motivation, and trajectory, a good coaching match is the single most critical factor in a skating career, whatever the goal is. And yet it's not one of the things you commonly hear parents comparing, or praising. You hear lots of praise for coaches-- "we have the top coach," "our coach has taken xx number of skaters to nationals," "he has the most students," etc. But the most important factor-- that wonderful coaching relationship-- is often ignored.
Level
Don't even. If your Jennie is in Freestyle 1, and "rival" Susie is in Freestyle 5, why do you even care. Everyone goes through the levels, at their own pace. I do not want to hear skaters compared based on their level. Sh! I mean it!
Financial
Out of your control. If Mary can afford four lessons a week, good for her. Work with what you've got, and don't teach your child to make excuses based on external resources.