Does anyone really think the broken parts, dirty carpets and filthy refrigerators were put in there by the dealers? That's the way they came from the previous private owners. Dealers will put the time and effort into cleaning and repairing a rig they fully intend sell on the retail market, but most of those rigs are either consigned for sale by the current owner or are trades that are going to be wholesaled at the next RV auction.
Those rigs slated to be wholesaled can be bought by a retail customer, but the dealer isn't going to bend over backwards to make it pristine on the lot because that is money spent that won't be recovered if they do wholesale it. And they aren't interested in a wholesale price from a retail buyer because the retail buyer comes with all sorts of strings and needs that the wholesale buyer doesn't have.
The consigned rigs aren't going to be cleaned or repaired either unless the seller agrees to it and wants to pay for those services. Most of the consigners are looking to get out from under the costs and obligations of that RV and they aren't going to spend one more dime on it. Not very smart since it makes those rigs much harder to sell, but most people aren't very savvy when it comes to marketing.