I’m not sure where you get that predictions have to teach anyone anything. If that’s what you want to do with your predictions, feel free. With mine, I’m simply saying what I think will happen, in a place that will keep a more or less permanent record of same, such that I can be called on it if I’m wrong.
And I do explain my reasoning, at length, for every prediction I make. In regards to Sanders winning NH, I base that on the level of Clinton’s support(very low) despite much higher name recognition than Sanders, plus Clinton’s inability to campaign as anything but a frontrunner.
And I also predicted that Sanders will not be allowed to win the nomination if Clinton falters. Another Democrat will get the nomination in stead, be it Biden or Gore or even O’Malley, even if the DNC has to go all-in for O’Malley.