A DM's feel for his game setting is not necessarily coloured by the ruleset he uses, as each DM approaches the rules in a different way. For those who do like the rules to support the way events in the setting unfold this is useful.
The attitudes of the players to the consistency of the setting are also an issue, and this rule can help in this regard as well, assuming it is presented in a constructive fashion.
Moving back to the idea of the bereaved NPC peasant whose wife has died, I would generally prefer a world where the possibility of actual resurrection never even occurs to him. He may implore the gods to bring her back, but doesn't expect that to happen.
In the light of the 4e resurrection rule I see the typical reaction being more like a third world peasant whose wife is sick and needs an organ transplant. Maybe expensive high-tech western medicine could save her but he doesn't know anyone who has been similarly saved personally, and neither does anyone in his village. Nor could his entire village afford the cost of either the transport or the treatment itself, and there is no guarantee that it would work.
The above analogy is of limited use, as for the fantasy peasant there is no tv, internet or phones, he's almost certainly illiterate and dependent on word of mouth and stories to learn anything.
Players and their PCs should be less blasé about resurrection magic in 4e, at low to mid levels, but some thought is still needed. Giving more conscientious PCs something substantive to say IC when bereaved NPCs beg them for aid is something that the DM should address when using this rule.