We only have one example of life. So why does all life everywhere have to have the same parameters to exists that we do? It could, for sure. And that theory is just as valid as proposing that the reason we aren’t visited is because all sentient life falls into a virtual reality hole or something when they become technologically advanced enough. When I see people looking at their phone walking into cars I think there might be something to it.
FReegards
Even if life was based on chlorine we should have been able to find it. I think we’re looking at the question the wrong way...