Well, one reason is for fun. A card with negative price, negative value, and negative VP!
On the mechanics side, while it usually does not matter, it anti-synergizes with venture or adventurer. It sometimes becomes a decision whether you want to play it before HoP.
Also, the card you suggested should just be a Curse, since there is no function when it is played as a treasure. Also the +1 buy is necessary, or the +$4 you get when buying it is usually not going to be very useful.
Note that you can empty the pile of the negatives any time you want, because you get +1 buy whenever you buy one. It is almost never a good idea to do so, however.
The biggest use for the card, I think, is to overcome some bad draws. It's like, okay, I can take a hit by having one more useless card in my deck, but let me have some extra money to spend this turn. I would imagine there are lots of interesting strategies around this card. For example, how about a turn 3 possession?