Buyers have been known to change their mind or get cold feet after they negotiate a purchase contract.  Often, the buyer will use an excuse to terminate by not responding to a counteroffer or refusing to buy due to an inspection finding.  In real estate, this is known as “walking”.  If a contract has been negotiated and all parties have agreed to all terms, a binding agreement exists and the inspection contingency has been satisfied, the seller does have legal options to enforce the contract but enforcing the contract can become expensive and tie the home up in litigation.  Therefore, the seller might prefer to retain the earnest money paid by the buyer and place the home back on the market.