Paraphrasing the words of Aldous Huxley: 20% of people are strong extremists with firm beliefs. 20% are going to follow whatever is trendy with worrying ease. The remaining 60% are people who will not take a strong stance.

When an extremist group gains traction, they can easily make the sheeps into their blind followers, but the other 60% of people may or may not follow depending on the situation. The 20% of sheeps are the so called "useful idiots", and in this case they are poor victims of TRAs ideology who mutilate their bodies. The 20% of extremists are those who yell so loudly about trans rights blablablah - but who will absolutely not mutilate themselves.

The silence you see from people is the 60% who just won't take a stand one way or another. They will agree with whatever the public will say they should agree with..... until it goes against them. And they key here is "until it goes against them". The more the TRAs ideology spreads, the more that 60% will notice that it does indeed go against them as well.