Most government agencies are non-profit. Ask someone you know who works for the US government and you'll get the same answer. No one gets a bonus just because the DMV makes more money from issuing record number of driver's licenses or vehicle registrations.
https://motherboard.vice.com/en_us/article/wjpkkx/doj-bitcoin-seizure-marshals-auction
According to Kessler, there doesn’t appear to be a legal reason the DOJ couldn’t hold seized bitcoins and sell them directly on a Bitcoin exchange for a larger profit rather than auctioning them off. It’s simply not the agency’s prerogative. Instead of maximizing profit, the DOJ tries to liquidate the assets for a “
fair market value,” according to its own forfeiture guidelines.
Things get trickier with something like Bitcoin, though, since the market value can fluctuate several thousand dollars in a single day, as Tuesday’s crash painfully reminded us. Depending on the way the market is fluctuating, the DOJ may end up making a large profit on the bitcoins without even having to take the coins to market.
A DOJ spokesperson declined to comment on whether it had ever considered selling bitcoins directly on Bitcoin exchanges, saying over email that the department doesn’t comment on internal processes.
In past DOJ bitcoin auctions, however, the bitcoins
sold for approximately their market value at the time, and there’s no reason to expect that the 3,813 bitcoins being auctioned later this month will be any different.