It's mostly about entrapment. There are a number of Christian cults in the US for example that also entrap people and they are no more deserving of respect than Scientology.

In its simplest form Scientology is owned and operated by people who have no interest in actually helping people, they simply want to entrap people using psychological trickery and blackmail and then suck them dry of money or use them to suck even more people dry of money. (Scientology's hatred of Psychology mostly comes from the fact that they heavily use Psychological trickery to deceive vulnerable individuals, and they don't want them to have any chance of actually getting help from someone else, or realizing how they've been manipulated.)

Despite what a hardline atheist like myself would like to believe sometimes, most people involved in the mainstream religions actually do want to help people and think that they are doing so. If nothing else, they provide comfort to those who fear or grieve. (And when I say 'involved' I don't just mean the people who use ignorance and false equivalency to excuse their attempts to belittle others or force them to conform to their own opinion of how things should be.) So while those religions are in my opinion do barely more good than ill, they are still on the positive side of the balance, whereas Scientology is most definitely not.