I didn't listen to the commentary, but I have a few thoughts about it anyway.
First, I agree that you cannot commentate on teenagers like that, it is inappropriate.
Secondly, I wonder why it seems so hard to find good sports commentators - usually my impression is that it is just laziness from the bosses, nepotism, and casual fans being used to certain commentators, so guys stay for ages although there are definitely others who could do better. But in this case the commentator duo had very little reputation, so one wonders why they were picked in the first place. I always think there must be so many people out there who would be able to do a very decent job at this. Are they paid so terribly? I thought Savitsky was doing a good enough job when he was once commentating on his own in English (his English also seemed better than Petra's from the short clips I heard from her, but maybe that's just me being German). Surely it would be even better if he got a second person to talk to, best someone who's a native speaker. Many current skaters do probably not have the time right now, but there must be many recently retired ones who are willing to do the job - no? When everyone is eager to skate shows because it brings some money, I would think they would like to take such a job. Did Petra and Graham also commentate on other sports during these games? That would be the most likely explanation why they were picked, if they have some basic knowledge in several sports.
Thirdly, there might be a cultural aspect. While I agree that youth competitions need to be treated differently, and that certain comments about athlete's bodies are just unappropriate in any case, German commentators tend to be very judgemental, will focus on the faults and not gloss over anything.

I'm sure many Germans don't like this either, but in general that's just the way we are. Sorry.