Just like anybody concerned about privacy is a crook hiding something, right? Or maybe they're afraid of getting swept up in an in-progress moral panic.
Further should overreaction occur, there will in fact be backlash against the conference and organizers. This is the internet. You know it is true.
And no it isn't comparable to privacy concerns. It is comparable to people rejecting theft laws because consequences for a wrong action are unfair and someone could be framed. I doubt you rail about how theft laws are unfair because someone could be framed. There can be reasoned discussion about actual penalties being too harsh or not harsh enough, but railing against the existence of such laws only benefits thieves.