What is the original purpose of Bazaar of Baghdad?
You get to draw two cards. This (at the time of printing) was 5% of your deck. At worst case, the two you drew were not as good as what you had in your hand and you will get rid of them, and chances also are that you had one card you would be willing to get rid of, or at least would be worth the risk.
You get to discard AFTER drawing the two cards. If the two cards you drew were crap, you don't have to keep them. It would be much worse if it was {t}, discard three cards: draw two cards.
You don't have to draw the cards you drew later. Key to the design of magic is the ability to make a comeback win, and this comeback typically comes with a top-deck bomb. Sometimes there's only one or two cards in your deck that can allow you to win, and the rest of your cards are just to keep you alive until this bomb gets on the board. So in that sense, this card could be {t}: draw two cards, then discard cards from your hand until you have one card left in hand. and it would probably still be sought after for that purpose. (Actually, the dredge crowd would salivate over this card even more if it did that...)