Qatana

Ballet Dancers are trained to "split" their bodies so that from the hara down thay are thinking "down" but from there up they are thinking "up and forward", partially because this is what gives us height in jumps and lifts, also because ballet was developed when people wore corsets and that is the natural posture of a corsetted body. But yes, this is why they seem top- heavy.
If I had only had ballet training I probably would have had to learn how to locate my hara and orient to "down" however jazz dance is also down oriented, and I'd had lots of yoga & belly dance and some tai chi before I started training.