The card you declined would go in the discard pile to be reshuffled for your search if necessary, which means you'd have to have 0 matching cards for it to fail (or the match would have to be in the discards in the first place).

The card you declined would go in the discard pile to be reshuffled for your search if necessary

To resolve a search, a player selects one of the nine search categories depicted on the search sheet and then reveals (to all players) cards from the supply one at a time, setting them aside. When a card matching the specified category is found, the player may either stop, taking that card in hand, or continue searching. If he continues searching, then when a second card matching the specified category is found, the player must stop and take that card in hand.

If the card supply is exhausted, shuffle the current discard pile to form a new supply and continue searching. If this new supply is exhausted, the search fails: the player takes no card in hand but retains his prestige/search action card for later use.

All previously revealed and set aside cards are then added face down to the discard pile. If the search was successful, the player then removes his prestige/search action card from the game.

If the search was successful, the player then removes his prestige/search action card from the game.

This is incorrect. Previously searched cards are not added to the discard pile (if a reshuffle is triggered) until that search is done. See BoW rules, page 6, bottom two paragraphs where this is discussed.

Is there any particular point to this rule? It seems like a fairly unecessary exception?

AFAIK, it'd be pretty cruel to decline a card you didn't want, have to reshuffle, and then be forced to accept it since it came up again. I believe the whole point is so that the player would be garaunteed to receive 2 different physical cards.

This is the main reason, but there were other reasons:

Another reason -- remembering that this case usually comes up only when there are few possible "matches" in the deck -- is to avoid the tedium of searching through a large portion of the deck (all misses), then reshuffling those cards back in and flipping many of these same cards over *again*.

A third is that for players who pay attention to what cards go by on a failed search, it's a lot easier to remember stuff that's gone by if you didn't -- midway through a search -- put some cards back into the deck. This way, everything that misses during a search is now in the discard pile at the end of the search. That's easier to track.

As for getting the same card twice, frequently when I skip the first card of a search it's a card that I'd be perfectly happy to get later. In those cases I'd prefer to have it reshuffled to improve the chances of getting it at another time even with the increased chances of drawing it again on the search.