Maybe I don't understand how exactly reviews work, but I think it is not necessary that an customer\clients needs to login to give a review, or do I not understand it?

Why and\or When is login and registering customer\client usefull? I mean he has to fill in his e-mail adress, so to contact him is default already possible...

I have now disabled it with css like:
#jreview-header ._right {
  display: none;
}
Or is this not an good idea?