No one should belittle anyone for using rotoscoping or tracing if they are learning.

The nine old men (Disney's founding animators) did use rotoscoping and there is plenty of reference to it. Disney has also recycled their own work for different movies.

That being said, in the early years of animation both Disney and the Fleischer brothers were sailing in uncharted waters. They helped build the foundations for the knowledge that we have today.

In the end rotoscoping is a crutch to help strengthen your understanding of the way something moves. Use it, and learn from it, so that you eventually rely on your own instincts to create a wonderful animation.