ok I'm just gonna give my take on safes spaces and say my opinion
from what I've seen I think people are against it because:
a) they have a possibility of becoming an echo chambers for political/social ideals
b) they have shown to possibly be able to radicalise people cause of the echo chamber
c) the news of people who have lost their safe space acting out in a very poor manner, like protesting by stopping 13% of student's of a certain colour of skin, screaming like banshees at their directors and professors, and all around being horrible people in general; I know that they are probably the minority as always but 10% of 1 million is still a very large number
d) creates an internal segregation and promotes the tribal mentality (example: my safes pace groups all love peanut so I believe we should all love peanut, those who don't love peanut are all wrong), it's more subtle than this but it has shown to happen from time to time
e) they are making people less accepting of ideas that go against their own
I ain't against safes spaces as a concept, like for actually people who need it,like it started out as mostly for people who where gay,trans or suffered from traumas or some form of physiological problems like depression and crippling anxiety, but I don't think they should be a wide spread concept since they have shown to actually do some harm like stifles the exchange of ideas and social abilities of the group
like you don't want to or forget how to make friends with people outside the group
it is also hard to change your mind about a concept when everyone around you is telling you the same idea over and over again
but that's just me as an outsider, never had a safe space, so I'm just giving my take from what I've seen and heard