They do take it serious. A lot of deals are where the house is only worth the $85,000 and they owe $100,000. I tried several as an investor and could not get the deep discount that i needed to buy and fix and resell. I have seen many listed properties where the Realtor adds in the listing that the sale is subject to lender discount and approval, Most of them are in great shape and are at the current market value, discounted below the mortgage balance.
The worse the condition the better the discount as Realtors have a harder time selling junk property.