Minecraft doesn't need money to be finished, it needs time. Hiring completely different developers to work on a different game will not affect the development time of Minecraft so I don't see how that is unethical.
The security holes is definitely an issue but that doesn't make Notch's criticism any less valid.
If I send you money to work on project A, and you invest that money on into some other project B while paying lip service to project A then yes, I would say you have a bit of an ethical problem.
Notch's criticism is hypocritical, and invalid on the grounds that he doesn't have enough information to say that the project is a "scam".
You're framing the relationship between customer and game developer differently than I've ever seen it. When I give a developer money for a game, I'm not "sending him money to work on project A". I'm paying him for the game.
In bold print right on the Minecraft purchase page:
"Please note that when you buy the game, you're paying for the game as it is right now!"
Anyone who buys Minecraft under the delusion that they're contracting Notch to build them a game is, well, delusional.
There are only two contexts -- that I can think of off hand -- in which you pay someone to perform a specific task:
* Contract employment
* Hired staff
Any time you pay a company for a product, you're doing just that. You pay for the product, and the seller gets to do what they want with the profits.
This might be a tenable position, except according to this interpretation of the Terms of Purchase they have not fulfilled their end of the bargain, since they do not provide me with a link to download the version of the game that was released at the time of purchase. This is really just a clumsy attempt at removing liability, not a reflection of reasonable expectations. Notch actively cultivates the expectation of continued and active support.
When you make your purchase you are given the ability to download the version of the game as is, fulfilling the contract. Until you point to something that specifically would force them to maintain the link beyond that your entire position is untenable. That they maintain a link to the most recent version in addition to having provided you with the promised version upon purchase is purely a bonus.
I guess it boils down to whether we think it's "lip service" to start work on a new concurrent project before the initial project is complete. As a freelancer, I work on many projects at once -- am I being unethical by dividing my day to several tasks in parallel instead of performing them completely serially on a first-come, first-served basis? I don't see that there's any neglect inherent in using some resources to explore avenues not directly related to the game. Is it also unethical if notch buys a luxurious replacement for something that he had previously owned which was adequate but not luxurious? Is this also a waste of the "advance" given by players?
While notch intimates that there will one day be a "final" version of minecraft, the only way that effects any minecraft owners is that they received a discount from the theoretical "final" phase because they purchased during testing. There is no contract or implication that final is going to be released no matter what, no refund available to users who don't receive a 1.0 as soon as they'd like.
I think it's silly to consider that an ethical violation. People who buy minecraft buy to play as it is, NOT to play at some hypothetical future state. It is not an advance where we receive a half-finish product with the promise of a finished product by x date.
The security holes is definitely an issue but that doesn't make Notch's criticism any less valid.