This is a totally pointless thread with a totally pointless OP because it is already totally fair.  It is fair because the buyer can pay whatever he want to whomever he wants.  It is his money.  If the buyer of signature space wanted to pay girls more than boys they could.  If you do not like how someone runs a signature campaign then you are free to not participate.

No one is forcing you to sell signature space to them.  You do not have to sell your signature space at all.

Quit you insesant whining.