Not all of our experiences are a universal bar to measure that with which we don't have experience.
The PvP servers are numerous because initial demand of PvP players is high. This demand may or may not fluctuate over time. PvP is here to stay, I don't see a standard genre MMO having no option for PvP. However there will likely always be an option for those who don't enjoy PvP, the content of the game.
Developers have a love-hate relationship with PvP'ers. They will be the loudest, most persistent champions of class balance. However they complain less than PvE'er about a lack of end game content.
Having said that I don't PvP. Not because I don't enjoy the "challenge" of which of my 8 to 10 buttons to press according to the situation, but because, as highlighted in this thread, there is a higher ratio of d-bags to respectful human beings in PvP. If you want to give the average internet tough-guy PvP'er a challenge, ask them to preform a "sit-up", or how to comport oneself respectfully as an adult, or what its like to be married. There is a reason they are motivated with such negativity. However, those are the loud, vocal minority. Most PvP'ers just enjoy an element of potential surprise and chaos thrown into what is essentially the standard tedious grind of levelling. They however almost never post in the forums.