I didn't say anything about the intelligence of the process, or the fairness - just it is what it is.
They want their money as fast as they can get it, and couldn't care less about being "fair." They organize the sales of their items in whatever ways will make it more likely to sell and to make it as easy as possible for them to get rid of those things because they are not in the business of managing assets.
They are allowed to bundle things in a way that allows them to sell stuff and minimize overhead. To wit:
If there were a ton of buyers out there who would be willing and able to buy 3000 $5000 cars in one go, then yes, you bet your ass they would lump the sales of cars they take in that way. But, there aren't many buyers out there willing to spend 15 million dollars on a bunch of shitty used cars, so they instead sell them in smaller lots or individually, because that's the only way that those cars will sell.
With bitcoin, there are a ton of buyers out there who would be willing to pony up the deposit of $200k, as well as who would be willing to buy lots sized of 3000 coins at ~500-1000 dollars per coin, and it's a LOT easier to sell to those people than it is to sell to thousands of people who are buying a single coin or whatever.
And, actually, this is in a way MORE fair than having it open to everyone. Normal people - read: not rich - would not be able to get their hands on a single one of these coins UNLESS the bidding got up so high that the people with tons of money decided that yeah, there's no potential for profit to be made by buying them at that price. So "normal people" wind up paying so much/taking on risk for the coin that moneyed interests aren't willing to touch.
And, to pre-empt any silly "how is this different than the car auction" comparisons again, it's different in that selling a bitcoin on an exchange is (probably) easier to do than selling a used car is. When there are easier ways to make money, shitty used cars aren't worth snapping up to keep away from other people. And, actually, if you ever go to an auction of non-shitty cars, they wind up going almost ALWAYS to someone who has plans to flip the car, not actually use it. "Normal people" aren't going to be getting to participate in the auctions that are about making money rather than just obtaining a shitbox to help with your daily commute.