Someone already posted this, but while it's nice to speculate as to (valid)reasons why PvP isn't done or needs work(like leaderboards, better matchmaking/scaling, etc.), the fact of the matter is that many if not most people playing this game don't like PvP, they don't like the feeling of losing(especially if they aren't in MAELSTONG MIRITE gais!?), etc.

They can do all the things to make PvP as enjoyable as in other games, but, if I might be allowed some plagiarism, "you can lead a horse to water, but you can't make it drink."

Personally, I love both PvP and PvE, and I totally think the rank 30-40 gear and that war horse are worth it, and that's my subjective opinion.