“When you eliminate any reason to reign in rampant desire, other than personal preference, most people (other than philosophers and their students) take that as license to do whatever they want.”
The best prevention of unreasoned greed is to provide the young child with love, safety, and community. This can be done very well in a religious community, but as you point out a philosophically based community can create similar results. Personally, I think it is better to do the right thing because greed, lack of consideration, etc. have been reasoned to be undesirable. I do not think the idea of doing the right thing because God will be angry is as healthy. No more than doing the right thing because dad will beat the s*** out of you if you don’t.
Actually the better self-discipline seems to result from very mild punishment or disapproval from a loved authority figure. When the child is about to repeat the undesired activity, they feel vaguely uncomfortable and don’t do it. Because the reproof was mild they don’t remember it, whereas they would remember a beating and perhaps not do it then, but when older and no longer with the beater. This is called “cognitive dissonance”.
If there is a God and He will be angry, it really doesn't matter what we think about it, does it? On the other hand, whether we accept His grace and forgiveness does.
Personally, my dislike of how things were set up by God kept me for years from accepting His grace and forgiveness. And I can't say that I like the setup even now. Things would certainly be different were I God. But then, things would have been a lot different when I was 8 had I, not my father, gotten to set the rules. I suspect the outcome would not have been good.
In any event, I usually accept things as they are today, not as I would have them. Accepting things the way they are seems to me, in the end, to be only reasoned course of behavior.