Well, if you ban and ostracize people for supporting some idea, then a lot of supporters for this idea would be people who are not afraid of being banned and os

Well, if you ban and ostracize people for supporting some idea, then a lot of supporters for this idea would be people who are not afraid of being banned and ostracized - and this category of people has a lot of conspiracy nuts, because they have nothing to lose anyway. You can not use the consequence of the suppression policy as a justification of the same suppression policy.