Platinum is sophisticated Bronze
A quick story: I have been playing league since the ending of season 1 and, except from some games with friends, i never really played ranked. I only started recently playing ranked and made it from silver 4 to platinum 5 in less than 2 weeks.
But here is what i see in platinum. Most of the games are getting so hard snowballed that you know they are lost in around 15 minutes. Im not always on the losing end, but in most cases 1 or 2 people in one team get fed really fast. Its what happens in most games in bronze. Someone gets fed and carries the game. The difference is that bronze players dont know how to capitalize on a snowballing player and end the game, while in plat people do know how to finish the game.
Im not saying that players in platinum are noobs or whatever. Actually i believe that there isnt much difference in skill between platinum players and diamonds. The difference is that most plats want to snowball really fast, some will manage it and some will feed, while diamonds are more "constrained" in their games, though there are some games where really stupid stuff happens. Platinums definitely have skill and game knowledge, but they are always greedy and blood-thirsty, getting them to make a ton of stupid mistakes they know they shouldnt do. And that turns most of platinum games, from what ive seen, to be more like bronze games rather than high elo.
P.S. Im not complaining about anything. I just wanted to say what ive experienced...