Everyone has a moral framework, whether or not it is examined the way Socrates would demand it to be. The issue is that you gave an example, which undermines your claim that you're not prescribing a moral framework: no example can successfully be free of every possible framework.
You claim that "life is the ultimate aim of moral design", but this is completely untrue. Many moral systems encourage the wasting of time and the dismissal of life in its various forms. Many moral systems, indeed, are not about the contribution of work to society and humankind at all. As a matter of nuance, this can be argued. (Is afterlife a form of life? Is life in the city or in nature? Is your time wasted if you intentionally wasted it? Et. al.)
In short, you actually are prescribing a specific moral framework. Yours. There's nothing wrong with this, except that you didn't even realize you were doing it. You've answered the relevant questions, at least implicitly, and so forgot that they were even questions to begin with.
> I do stand by the idea presented there.
You're not wrong, exactly. Take Richard Bartle, who has been pounding out a very similar message to the game community, though you'd have trouble recognizing it.
His message is simple: know why you do things. Why do you have levels in your RPGs? MUD1 (his game) had them because they represented the possibility of social mobility to a pair of British country-born schoolkids annoyed by their circumstances. But most designers only have them because well... that's just expected. Their decision stands unexamined; often unrecognized to be a decision at all.
He did not need to bring up morality, because it's not the point. The point is that, when you do things, it should be grounded in a solid self-aware understanding of what and why you act. Design intentionally. Think about the details. Care about consequences. Test everything, hold onto what is good.