The Mac isn't going to magically disappear once he makes the Mac VST. .... If things were clarified a bit further by him, it'd certainly help the general attitude.
I think this is the key point that makes this a donation and not an investment or even pre-order when combined with his business model.
Backers don't get anything different to non backers if the project goes ahead. The incentives for backing are that A) they want to help him, and B) they want access to GVST plugins on Mac.
Since GVST plugins are free at the point of download non backers will get access to them for free once the project is completed. This means financially non backers get a better deal, should they choose to not donate (which I'm guessing is the norm).
Also, upon completion of the project he still has the Mac, and he can make further money through further donations to GVST from users of the plugins.
In this scenario, if he reaches his goal he stands only to win now and to possibly win more in the future.
What is missing is where the backers win VS the non backers. Since he doesn't charge for anything he can't give the backers anything in this scenario.
It would be a different situation if he did charge.
Say the plugins were $50, and he was going to do this project at $30 per plugin - then the backers would win VS the non backers. There would be incentive for the backers to back early, and the issue of him making further money from sales after the completion of the product wouldn't be as much of an issue because the backers have already had their reward. In this scenario, the Kickstarter project becomes a 'pre-order' whereas right now it is basically just 'donations'.
I'm not angry and I am a bit skeptical if I'm honest. But mostly I'm just interested in how this business model changes the value of the products.