How would replicators and holodecks by themselves make it easy to be perfect? Couldn't replicators make it more difficult to understand the worth of things, and holodecks make it easier to become unsocial and alienated? Wealth and leisure alone do not make one a moral a person.
It's more the issue that I am a believer that "civilization is needed to be civilized." It's not that people are necessarily more primitive but it becomes easier to be compassionate and peaceful when there's less concern about day-to-day survival. I don't see this as a flaw, merely a state of reality that absence and struggling to survive makes it hard to care about things other than survival.
Finally, Phipps, if the remaining survivor of a race is a mass murderer, I say it is genocide and wrong to kill them in the 24th century. Given their level of psychiatric and genetic-engineering/cloning tech, I'm sure both the murderer and their race could be saved. Not that most people would want to.
I'm not a believer in the death penalty nor do I approve of WMDs. However, I enjoy postulating questions that put us in tough places. In the case of our hypothetical, "last surviving member of a race is a scumbag" I actually do believe there's a point that the loss of something unique in the universe is something to be avoided (so says Data in MOAM).
My point was more a "devil is in the details" sort of question. Genocide is the most horrific crime in the history of the world but operating from the assumption that every single Founder is a consenting adult in a campaign of mass murder and conquest--makes the thing more questionable than I thought DS9 was meant to do. I'm actually rather glad to find out I was wrong since I always felt that was troubling.
As I mentioned in my review of the book, I want Star Trek to always come down on the side of peace-making.