in your openion, Why until now binance does not list dogecoin in her exchange

It caused by this coin can be considered as a zombie coin which is not having a team that will continue the development. binance will only try to add coin if that was having a working product. Remember about it's not free to be listed on binance exchange site. You must deal to pay some million dollars as the listing fees. this has already revealed by some icos which already listed on binance.