Well! Because you have no idea if it was ever fertile and no idea how old it is. Being in the street would have left it open to infection, even if the shell was intact. Let's say by some miracle it still contains a viable embryo. With its shell so badly beaten up it will dry out within days, killing the miracle embryo.
I'm just answering your question and trying to save you some time and disappointment.
Put your energy's into some viable eggs. I'm sure you'll love them and make a great quail mum.