I can see at least two:
1) The site is not worth it, even if it could be a valid collateral (it's not), so your loan is a disguised sale.
2) Technically you could double dip - sell the site while it's being held as a collateral and stiff the lender or the buyer or both.
Since OP here already tried to sell it and get 0 bids, I guess that he goes for the option No1...

@OP: Better lock your thread before you ruin your account from the start.
