If you raise the age of seniors, then all you'll do is further decrease the relevance of the seniors competition. Juniors will be the place where the "real" best singles skaters are found.
I agree with you to an extent. That's why I'm not really sure if I want the age for seniors to be raised. On one hand I think it would make sense and it would be the right thing to do. On the other hand, it would possibly make the junior events more interesting and exciting than senior events and that would look bad.