I remember there being a site that had interpretations of each MSG, on how supposedly starting with 2 Kojima was trying to troll his fans. Raiden is supposed to be a representation of average gamer, how he's just a kid that wants to play with guns, and imagines himself a great hero. So most of the kids that called Raiden pussy were supposedly offending themselves.
And then after Kojima gave in and made 3, he made it exactly the way people wanted with "awesome" hero and lots of guns, and again that was supposed to be a satire on gamers being obsessed about guns and characters with 5 o'clock shadow and gruff voice holding them. So the game had things like character heartbeat increasing when he looked at a gun hold by
female npc but nothing happening when he looked at her breasts. Basically that was his outcry to the gamers "look that's how shallow you are, you just want guns and explosions and over-the-top characters" in hope that they will realise how immature they are.
Of course with most of console-tards being what they are they completely missed the point, deciding that it was Kojima making the game how it should be. So he gave up and just made 4 with even more guns and stupid epic bullshit, and also made Snake a dying old man so they can't force him in making another MSG.
Of course then this could be just an overinterpretation, and Kojima may be nothing more than a glorified fanfiction writer.