Home inspections have traditionally been for the benefit of the purchaser. Pre-inspected listings benefit all parties - purchasers, vendors and Realtors.
If the home inspection is performed prior to the house being listed, all parties will be aware of the physical condition of the house before an offer is drawn. There will be no surprises after the fact.
Deals will not fall through.
As most real estate agents know, renegotiation is very difficult. Vendors have already mentally sold the house; purchasers are suffering buyers' remorse. Egos, pride and frustration can muddy the already emotional waters. A vendor who pays for a home inspection will be further ahead than one who has to renegotiate. He or she may even sell the house faster.