That's not a safe assumption to make of Kickstarter. If the intent is really to treat everything as donations then every tier should include "acknowledgment as a backer". As it stands today it's only stated for $1000+ level and that's not really acceptable if you consider everything a form of donation. I saw very little in the description or "rewards" that really treated backers as genuine donations rather than just simple pre-orders (that includes access to betas and/or user testing). It was rather confusing compared to nearly every other project I've contributed to on Kickstarter.

You're right that the tiers can't change much now, but the way it was structured and worded is indeed discouraging. I know I was certainly discouraged as a result, and I'm currently on the fence as to whether to contribute now or wait and see how it turns out. If this project doesn't succeed in making it's goal I would really recommend looking at the more successful software projects in detail and notice how they go out of their way to message and recognize backers in a way that makes them feel like their genuinely contributing, even if only in spirit, and orient their rewards accordingly. Adding buttons, logo stickers, t-shirts, posters, etc. are the kind of things that a community of supporters will desire and from what I've seen so far, go a long way in encouraging larger donations.

edit: removing suggestion to rollup rewards due to their potential for complicating things.