You are quoting the first post someone made in a blog about a game that was slated to be open PvP with permadeath ever since it was revealed to be in pre-production over half a decade ago. A game that is being made by a company whose only successful product up to now is a game whose cornerstones are non-consensual PvP and player looting - and, what's more, perhaps the only actually successful such game outside Asia.
Sorry, but not only is that post biased from the start due to the game it's about, no matter how much the author calls himself a carebear, I also don't think it holds any more weight than any single post here on these forums even if you disregard the bias.
Besides, I really disagree with that author as to the need of griefers in a game; I see nothing that an NPC can't provide in a way that is better for the game as a whole and less prone to drive players away. If the author was right we would have a lot more full PvP MMOs out there, and the ones that attempted that role being more successful, instead of the current landscape where only EVE is able to thrive in that genre and the rest seem to languish, barely bringing enough cash to keep the development team active.
To be fair, some of what he describes is true. Adversity can make people band together, create strong bonds, drive people to experience things they would have avoided. The problem is that most people won't; a game is not real life, so unsatisfied players can just leave the game, find something else to play, and go have their fun there; if the game makes too many players take that choice, if it attempts to take too many players too far out of their comfort zones, it either dies or has to change ways.
Take UO and the MMOs that followed it, for example. UO was used as a basis by about every big MMO of the next generation, including EQ, WoW, and SWG; most of those MMOs actually included developers from the original UO team. Ever wondered why the kind of free PvP that UO had at first was not replicated in those games? It was because every publisher, every development team, and even the ex-UO developers now part of those teams noticed that, despite whatever positive elements the open PvP allowed to bloom, the negative elements were far more prevalent, both driving more players away than was acceptable and drastically increasing support calls from players that couldn't enjoy the game due to the antics of PKers.
Even UO backed down from it's open PvP origins; back in 2000 UO's player base showed signs of being stagnant, poised to fall, when an expansion was released adding a new world, Trammel, where PvP was only possible by consent. After that UO's player base greatly increased, almost tripling it's previous numbers in the next couple years before finally starting to decline.
The way PKers can drive overall population down was known from the time of the MUDs, before graphical MMOs were born, BTW; many such games were killed because PKers started to proliferate, driving the rest of the players away, and at the end the PKers left due to lack of prey. Richard Bartle describes this process, and what leads to it, in it's 1996 paper titled "Hearts, Clubs, Diamonds, Spades: Players who Suit Muds" (
http://www.mud.co.uk/richard/hcds.htm).