Don't some groups once seen as "cults" often move more into the mainstream, becoming generally respected sects or religions?

Yes. There are certainly examples of groups that were once perhaps thought of as "cults" that have evolved into relatively mainstream sects or religions. Such examples as the Seventh Day Adventists once led by Ellen White, or the Mormons officially now known as the Church of Jesus Christ of the Latter Day Saints. But it is also important to note that some groups, which may have once been labeled as "cults" continue to be controversial due to their unsafe or destructive practices. Two examples of groups that continue to be problematic and often destructive are the former Russellites, now known as "Jehovah's Witnesses"--who have prohibited organ transplants and blood transfusions resulting in numerous deaths. And the Christian Scientists founded by Mary Baker Eddy who often reject medical treatment--again resulting in the loss of life. Some groups may say they have renounced unsafe or destructive practices--only to be exposed later as guilty of the same extremes and abuses.  more