As a person who played on both sides. What I can tell you about PvE is:
1- It is a win-win kind of scenario. Almost no one loses, which is the biggest bother in PvP. Even harder content, if you have a dedicated group that understands the game mechanics well, can be burned down relatively easy.
2- It gives better change for all classes to perform. In PvP half the game spec are down right unviable.
3- It does not require major understanding of every single spec in the game. Closet thing in PvE is boss fights, which are relatively easier to understand and much more predictable.
4- It is a lot less egoistic, and much more friendly. I am in fully auged obroan, and I get really frustrated when I see ppl in WZs with 26K HP and 1,600 expertise unstimmed. In PvE there is no such thing. There is a gear requirement, and most people can easily out gear the highest content, so it is just the process of them understanding the mechanics.
5- The gearing in PvE is straight forward that people can understand very easily with gear rating and clear system. In PvP gearing is so convoluted, that you have to tinker with 20 million things in order to be effective in WZs with low gear.
6- PvE has no entry barriers. You have been gearing up for it since level 1 and everything in the game educates you on how to gear up. Even if you are not good, you can still do most content easily. The skill and gap required to compete effectively in PvP is not easy to attain and nothing educates you to improve, except joining WZs and getting obliterated.
Having said all the above, I prefer solo PvE content or FPs, over ops. I got extremely bored in ops. I hate 16 man ops in particular, cuz there is so much skills flying, my eyes get fuzzy. In addition, I prefer that fights break every 1-2 minutes. In ops you can stay in a constant fight for 10+ minutes. Also you need to block 2-3 hours to get anything done, were in PvP and PvE solo content/FPs, all I need is 1 hour.
This really just speaks for how bad PvP is in this game. When BiS is a *********** matrix cube and wearing a 61 hilt buffed up there's a problem. The closest PVE has to backwards BiS is for dot/healing specs that can utilize the double proc on kell dragon SA relics.