It's good to have a bit of randomness and some other factors besides pure team quality. Sure, having a higher quality gives you an advantage, but it's not impossible for a weaker team to beat you if they know how.
I'm not sure who it was that posted about the linear thing earlier, but it's true that it shouldn't be so linear. If it's changed so that everyone "gets what he deserves" as Adel says, then many more managers would quit the game, only the rich token buyers would stay as they can buy all the best players and just win every game.
It's not anything in the engine or from the developers to get you to buy more tokens or anything like that, it only serves to balance it out a little so that token buyers don't win everything, or else that'd take all the fun away.
What about value for money, you might ask? It's your choice whether you want to buy tokens or not, knowing that they won't guarantee you success.