Almost all of these bikes are from insurance company "totaled" vehicles, bank repossessions, police impounds and the like and not from individual private owners. That is why they are often wrecked, vandalized, burned, flooded or generally in poor shape. Many have salvage titles or are deemed to be irreparable and are to be sold for parts only. That is why you don't see very many bikes like these on ebay or CL and such.
All the fees and charges are just the way they do their biz. They wouldn't be making much in just commissions for the low $$ these kinds of vehicles bring in transactions even though they probably do a fair volume of them. CL, ebay and the like DO a very large volume of sales and generally speaking the stuff being sold is not total crap and often brings a decent price for the transactions. So for the commissions and services they provide, they get by very well thank you.
There might be folks out there that make it a business to get these "distressed vehicles" for flipping. (fixing them then selling them hopefully at a profit) But they would have to do a pretty fair volume of them to make it work well. I thought about it once upon a time. But it would involve the need for much more room than I have access to, more tools and materials than I can afford or have adequate knowledge to use and, well, it would involve more work than I am willing to put into it. I retired to get away from doing so much work. BUT!, for an individual, it could be an opportunity to get and fix a bike for relatively cheap every now and again as a hobby.
just my $ .02