You know, that argument would carry much more weight if the rewards and tiers were announced after all the pledges were made. Given that they are known before the pledging, then there is certainly a subset of the backers who are investors - they put in $15 with the expectation of a gain on their investment (That is, they expect that the game will have a value of > $15). For higher level backers, it is harder to argue their status as rational investors as they start falling more into your "supporter of this type of game" category unless they are able to argue the value of all rewards for their tier relative to the backing amount. You don't get a say in the direction of the game for your investment, but that doesn't stop it from being an investment.
Also, given that the rewards were known before pledging the argument that these are not pre-orders is also absurd. You are putting money down before release (before production!) and will recieve a copy of the game. This has less certainty or guarantees than most standard pre-orders, but any tier which recieves a copy of the game is a pre-order, even if it gets other stuff along with the game(s). Pre-ordering might not be the primary purpose of the donation, but as long as you select a reward tier with a game, it still is one. Arguably, even from the production side, the whole point of much of KS is exactly the same as preorders - ensuring a minimum interest / run for the item.
At this point, you could argue that the decision has been made so any more discussion of it is moot and that such discussion should cease once the decision was made.
However, this started with the thread where the developer was asking for feedback on this reward that was expected to potentially controversial. Identifying if there were enough objections to that was, as far as I could tell, exactly what was being asked.
