They don't start out so harsh--the leaders are usually charismatic.. great speakers, who know their target audience on an intuitive level. (And I don't mean MBTI style intuitive necessarily.)
They collect broken people--people seeking something in their lives. People rejected. People humiliated that want a new life somewhere else. That need help. That want to get away from their current status. They take you in, with acceptance, and warmth, and caring, and understanding.
.. but it doesn't stay that way. You realize the only reason they care is because you must do what they say and do. You must think as they do. You must assimilate. Some people don't have a problem with this, and easily shed their old lives for new ones. Being accepted, and validated, is a powerful thing. And most strangers don't care to do this for other strangers.
But there's always a motive. People don't accept you for no reason at all. Some because they have moral obligations to fulfill. Some because they want to control you. Some because they like you and want to be with you. Whatever the reason, there is always a reason. But by the time you're joining a cult, you're at the point that you don't care.. or even worse--you do, but you can't see.
Frequently they start out as innocent things. Sororities. Fraternities. Group meet ups. Religious discussions. People can tell you and name warning signs of suicide all the time, off the top of their head, like its muscle memory--same with pedophiles. But no one wants to believe they'll ever encounter such terrible things.. so they don't actually see the warning signs they've been trained to notice. They're too subtle, and too inconvenient. How do you define sadness? Anger? How do you notice someone depressed vs just having a case of understandable blues? How do you know how much stress people have? It's hard. And it takes bravery to approach someone forwardly like that. Something many people lack. Most people, I'd argue. Cults are the same. You know what cults look like--until you're stepping into one. Then they look warm, inviting, maybe a little out of the ordinary.. but for a mind open to suggestion and not so firm in conviction.. it just looks like a group of friendly people that want you to be with them.
And it only takes a few. Especially for the breeding cults. The children are taught from birth. It's not even an issue for them. It takes a strong willed, intelligent child to break free from the constraints of their entire known society and parental figures. It's a sad thing to see, and happens frequently.
Before you know it, you're isolated.. and even if you wanted to leave--you can't. Everything you have was given to the cult. Your family abandoned you--or more like, you abandoned them. Your identity, who you are, what you have, how to survive.. it's all there. People have a hard time moving their households when they WANT to move.. and procrastinate on small tasks that make their lives better. Yet they expect people in cults to overhaul their entire thinking style and way of life as if it were so easy. It isn't easy to be uncomfortable--and stay that way--and realize who you are was nothing but a scam created by someone else. It's wrenching. In more extreme cases, they hold you there physically against your will. They don't feed you, and weaken you so you cannot fight back, and hold you down if you try to escape and lock you in. They physically isolate you so you cannot walk anywhere for civilization before dying. It's a terrible thing.