Dont confuse the status of Raiden in MGS2 with MGS4. Two different Raidens showing him in two different perspectives, one human one cyborg. I liked when he became a cyborg. Less emotion, more action. The coolest parts of MGS4 were Raiden's untouchable parts where you viewed everything he did via cinematics. Fans wanted to actually play as him and I doubt that was something Kojima, himself was ready to accomplish with his studio.