Short sale with requirement of an all cash offer ?

[Alex K.]

I put in an offer on a property for 450k and the comps say at least 600 and up for similar properties . But , the agent wants all cash offers only for a short sale !? Why would an all cash offer matter for short sales ?

Also , I had to put my offer in blind because the property has tenants and the offer had to be put in , in order to even see it . .. ?

Anyone have any reason behind this from the listing side ?