People (idiots) prefer therapeutic to preventative because of shitty/misattributed confirmation bias. If they get the shots and don't get sick, it's not because of the shots, it's because they weren't ever going to get sick anyway. If they get sick, take something, and get better, it's because of whatever they took. They can't see the vaccine helping them, so it isn't happening, and if it isn't happening, then it's worthless, and if it's worthless but someone's trying to "make" you take it anyway, it's cause they have an ulterior motive.