They technically remade MGS with Twin Snakes for GameCube. It was a big project at the time and they didn't earn quite as much. I don't think they wanted to go back in and do it again. It would be something highly unlikely due to the rough business with Kojima and Konami, Konami not showing much interest anymore in their older franchises, and for the NTSC / PAL fans...we'd need the original English cast back again and an enhanced soundtrack. It's asking a lot and not impossible to pull off but so much has gone on since the game's inception.
If there's enough support and Sony sees money worth investing into a Legend of Dragoon remake; they'll do it. That game was amazing and has never been ported. Right now, Sony (or Atlus???) is working hard on perfecting the remake of Demon Souls and so it could be some time before they get around to Legend of Dragoon. It's about finding the best games to present prior to, during, and shortly after launch day. That's another reason why some of the remakes may need to hold off temporarily.