I think the problem is the cognitive dissonance of this kind of scene coming right after the last few issues, which were most certainly not Marvel Adventures grade material (in terms of lighthearted adventures). That final scene would fit in a Marvel Adventures book, in fact I can easily see Ben, Reed, and Johnny crowded around a dentist working on Sue's teeth.
I dislike that last scene for the main reason I stated: it completely destroys any future pretense of Stargirl maintaining a secret identity. The dentist will blog about it, people in the waiting room probably took pictures with their cameras, and I'm not even going to address the issues that arise because of the two animals in there. This scene...if we're to take JSA as a serious book, which I've assumed to this point because of the various tie-ins...paints a target on the entire Whitmore family in a way without parallel.
Not that it matters, since I don't read JSA. This post is mostly to defend any potential attack on the Marvel Adventure books.