They over value your house when selling. Makes the sellers feel good because they are being told how great your house is and how much it's worth. Feeds into the seller's ego.
Then when the house doesn't sell right away, it's the 'well the market is real soft right now, we should think about lowering the price'. So when you end up reducing your selling price $20,000 for example, you lost $20,000, the realtor lost $600 in commission. Who lost the most but initially you signed up with them for a certain period of time because they were blowing sunshine up your skirt. Now asking you to lower the price to more of a reasonable price, hardly costs them anything, but costs you a bunch.
I've seen this more than once.