Should we forbid Catholics for the same reason?
Your answer lies in the distinction between cults and religion. In a nutshell, cults exert control over their members such that they compel them to behave contrary to their own interests.
So the modern, practical answer to that question is: No.
Your average Catholic is no threat and is very likely to be acting in their own interest, free of undue influence.
The Catholic Church, having had nearly two thousand years to brutally weave itself into society world-wide—has all but abandoned the behavior described above—with the exception of its clergy and people involved at the operational level of the church.
Indeed, they've outgrown the practice of using coercion at the level of the individual member, and now wield power as a small nation state with global reach.
>Should we forbid Catholics for the same reason?
If they're formerly or currently involved in any significant way at the operational level of the Church, then you may have an argument in the affirmative there. Albeit, a narrowly-scoped one.
LGBTQ and Homosexuals are welcome to leave at any time. Those who join Catholicism, clearly understand the Catechesis (as they have to go through RCIA) and if they conclude that they don't fit, they can go to another denomination.
I went through RCIA and we had people who literally decided to leave the night before Easter Vigil and no one harassed or bothered them.
You are welcome to disagree with the Church but to compare Catholicism with a Cult is disingenuous.
Have you heard of the Spanish Inquisition? Hundreds of thousands of Jews and Muslims forcibly converted to Catholicism or faced with ethnic cleansing, with mass executions claiming thousands of victims. Or the Portugese inquisition? Or when Galileo was imprisoned for life for heresy against the Catholic Church?
Not to mention what Catholicism did to the Americas...
Or for more recent examples, how about when the Catholic Church took two Jewish children whose parents had been killed at Auschwitz, converted them to Catholicism, and refused to return them to their surviving relatives, resulting in a nearly decade-long post-war manhunt where the Church hid the children in a variety of monasteries under false names while refusing court orders to return the children, telling them that their entire family was dead — when in fact their sisters and aunt had survived — under the direct advice of the Pope? https://en.m.wikipedia.org/wiki/Finaly_Affair
Except for kids, and—historically—large swaths of various populations.
However, what you describe certainly does create the conditions for that kind of behavior to occur organically. Lack of inclusion by nature will result in members being shunned. Personally I think religion in any form has zero business being exclusionary. The counter-argument there I suppose, would be that human group cohesion is—by and large—exclusionary in nature.
Perhaps morally there is little distinction, and organized religion has just had time to establish itself and exert power upon individuals in more subtle ways.
Circling back to the original topic: members of a small cult are far more likely to act—in unision—contrary to the interests of an organization that employs them.
So you're saying being a homosexual is not in one's self-interest. As if it's somehow inherently bad.
Did it ever occur to you that the supposed propensity to addiction and self-harming behavior may stem from the fact society's historically been less than accepting of homosexuality, owing in no small part to religion?