Right. Not only that, but even so, it still needed to be a torpedo as we clearly see Luke's torp turn the corner. Even if SW used B5-style thrust vectoring, getting a straight on shot long enough to hit the reactor would be one in a million, if not one in a billion or trillion angle. Even without TIE fighters coming after you.
Still, DS2 supposedly fixed that flaw... if it had been completed before the Rebel Scum attacked, err... that is were lured into the Emperor's carefully planned trap (which was all foiled by Han Solo stepping on that twig).