tomimt: I do think in some cases there's some fault in the devs as well, especially if they've oversold their project and promised things they're not able to deliver. Though I wouldn't always call those cases as scams, especially if they manage to deliver a product.
A scam happens when they take the money and run.
Or, if the reward is something which in no way corresponds to what was promised.
But in all other cases, it's not a scam. What these projects are looking for, is money to develop the products, which means that during development, there may be changes. What they are showing is not the final product.
tomimt: Then again, if the product is clearly unfinished, like if a game that is suppposed to be a full game just ends with out conclusion, then it might be a scam.
Ending without conclusion doesn't mean a scam.
Or, would you say that games like A Vampyre Story or Runaway - The Dream of the Turtle are scams?
Both are full-length games, but neither game completes the story to any fulfilling conclusion.
Of course this is also a marketing trick, as some gamers feel they "must" see what happens next.
But Vampyre Story Kickstarter probably failed partly because it had a "scammish" feel to it.
It would not complete the story of the original game, but instead be an episodic prequel, which in the worst case, would mean another incomplete storyline for the same franchise.