You make it sound like they are doing some thing wrong, when theyre not. What you find is there are 2 different types of dancer, the ones who glide and the ones who bop.
I think the ones who bop are the ones who have probably done a lot of hand bag dancing in the past and it's just become a habbit. But to certain music ie not blues or anything like that they look fine. But as with anything if one of you is dancing smoothy and the other bopping then it will stand out and may be awkward to lead or follow but hey thats why ceroc is fun as you dance with people with different styles.
Although IMHO technically speaking the lady should change her style to match that of the man she's dancing with
