Was a remake really necessary?

I went to see the remake of "Clash of the Titans" the other weekend. After viewing it, I'm not sure why anyone felt it necessary to do a remake, except that it gave the film maker the chance to do some awesome special effects. Basically, the story is the same as the 1981 movie: young Perseus must go on a quest for the head of Medusa, which is needed to turn the Kraken into stone before he eats Andromeda and destroys mankind in the bargain. Don't get me wrong, the first movie did its part to mess up the whole Perseus myth; this film absolutely muddies it up even worse. Many changes have been made from the original film, most of which were unnecessary and disappointing. The addition of Io was totally pointless, and her storyline destroys the end of the movie. In the original movie, there was more interaction between Zeus and several of the other gods, including Poseidon, Hera, and Athena; here, Zeus and Hades are the only gods utilized very much, and in fact, the picture becomes nearly a showdown between the two, with Perseus in the middle. The little mechanical owl from the first film is used as a throwaway bit in this movie; Perseus doesn't want to use the magical sword given him by Zeus; the huge scorpions have multiplied and are used as transportation; the old philosopher character is gone; the three Gray Ladies(Stygian witches) are monsters instead of old women with only one eye between them; Perseus is the only character with a buzz cut--why?; the whole legend of Danae has been changed--now it is her husband rather than her father who puts her and her child into a chest and casts it into the sea and in this film Danae perishes; you never get to see the entire Kraken as in the first film; the love story between Perseus and Andromeda is gone, and so on. On the plus side, although I enjoyed Ray Harryhausen's special effects in the original, the effects in this movie are quite good. I really liked what they did with Medusa, especially keeping her face beautiful (except when putting the eyes on you) and having her laughing as she chased the characters; and the winged horses were great, especially Pegasus, although why he was referred to as "the" Pegasus and made black, I'll never understand--another unnecessary change. Overall, the only reason to see this movie would be for the effects, as the story is definitely lacking from both the original Greek myth and the original movie. If you saw the 1981 film, don't bother with this one unless you are really into special effects. If you must see it, wait for it to come out as a DVD rental.