@matigo I think people have an inherent terror that something might happen somewhere to someone else that they are not involved with. It's an instinct to find out what's going on, they don't think first. But if they baulk at the slightest barrier or requirement of effort, it's an indication of how shallow and token their interest is.
Of course, there could be a bug in your sign up and people could be falling down the back of the sofa…but I doubt it.