A famous vid is going around you probably seen it. https://www.youtube.com/watch?v=-919...ature=youtu.be
Whoever has more people on the zerg, provided is abismal difference, wins and even so not always. But that is not how the battle is won because the battle is not centred in 1 single place. You can check here http://www.youtube.com/watch?v=0pfO5s9pi0c. That dude alone was holding and sometimes owning alot of people, if he had a small team with him he would certainly win against the big zerg. And since he doesn't I would bet somewhere else in the map his fellow server-mates were breezing thru, . Low participation will lead you to the bottom of the ranked system of WvW so basically at some point (which I think by now is pretty settled). I haven't been actually farming so I won't say much about the PvE you said but I think about now they are a little bit more spread around the world since rewards are getting higher (still not quite there tho). Now if you really want to sit with 20-30 people around for "easy" mindless play sure you can, but that's a player choice (which I loath xD).
All in all of course all games are enjoyable for the right set of people. For my wife Gw2 is so hard that she just doesn't play too much (even tho she tries at times) while Dungeon in WoW she heal like a pro, different skills and needs but still "balanced" enough and similar enough through different combat systems that they can ,and often are if you read threads here, compared yet both are good in their own way. I think there is more to do from what you imply after hitting max level because it's pretty much discarding the idea that you could just do what you think it's fun primarily because of that "criticism" that comes from WoW-like mindset.