haha Stitch!
Well, I didn't really get further than the first page before I formulated my own answer.. I pulled your reply out above because it sort of rings true, even if a little off the mark a bit!
So I was eternally put off PvP playing EVE online. That game endorses PvP so far that entire swathes of the game are unavailable if you stay in higher (supposedly safer) security areas. BUT then the PvP eccentricity of the EVE universe takes a more sinister swing, and it's this swing that is entirely contradictory with my ethos, and personality. Therefore rendering the game unplayable for me, even if the concept and actual potential of the game is utterly fantastic.
When you get a PvP oriented game, you ultimately attract a certain nature of gamer. PvE co-op games tend to bring people together, work together for a common goal. In Elite Dangerous, Mobius has tried to accomplish this (as far as the mechanics allow), I always subscribed to that the backdrop of Elite Dangerous is that mankind has breached the barriers of technological limitation.. Mankind is preparing for the most adventurous proposition yet.. Exploration of the milky way galaxy. It's this philosophy that attracted me to ED. FDEV provided me the game modes to avoid everything I despised in EvE. In EvE there is no let up. There is no reprieve. If you log off to go to sleep in EvE, the next time you log in... everything has been attacked, and you know all that you worked for is trash.
PvP games bring out the worst in human nature. Conflict between factions, people, races and religion is rife enough in the world, without trying to endorse it further in games, or somehow accepting that human nature is entirely compatible inside a computer game. It isn't. Take this for example.. It's what happens when PvP takes on a whole new dimension, what kind of person takes self righteous prophecy FROM A GAME so far that they come up with this:
http://www.minerbumping.com/p/the-code.html
ED is clear proof of the fact that PvPers with direct human conflict in mind dominate. When it is no longer safe, or the perception that it is not safe in ones minds eye, then the human instinct is to seek sanctuary, or simply move on to somewhere or something that is safe.
Circling back to what Stitch said.. the fox among the chicks causes a level of hysteria. Some of us play games to avoid this side of human nature. Ergo we finally answer the OP question. Why is PvP not popular in ED? For me, it's because it's against my ethos to cause harm, and suffering to another being of intellectual self awareness. Not in real life, and not to another player sitting in real life at another computer in a fantasy setting. There is still another person involved, and that person has feelings. To me attacking someone in the cyber world is equally as bad as in the real world... Hey mugging someone in the street for £1000 imo is as bad as hacking their bank account and taking £1000. They're still violated, and still emotionally suffer as a result.
TLDR: another player is a human being, and if one takes pride in causing distress (salt, for example) then it starts to steer the game in a direction I'm not comfortable with. To a certain degree I'm ok with it... but beyond that, no thank you.. especially considering Elite Dangerous exorbitant prices on being victims in the game. Being victim in ED is ludicrously punishing, with absolutely laughable consequence to the attacker, it feeds salt, and it makes players adversely react, which ultimately the more poisonous players need to make themselves feel better.