Original sentence: Amongst both practitioners and skeptics there is considerable variation about what is regarded as NLP and what is not.NLP is often considered controversial and is at times criticized as unproven or pseudoscientific by those who watch for fraud, exaggerated claims and unethical practices
Edited sentence: NLP is criticized by many in the scientific community as unproven or pseudoscientific, and amongst those who watch for fraud, for exaggerated claims and unethical approaches