@Nathaniel: true it's rather rare to find a party for dungeons however I believe there's also another reason to it, not just people prefer to solo grind. Tbh for levelling up, at least in sturm, it's faster to duo or trio all the way for mobs than running alone and grind a few mobs only. People solo it mostly for farming, I think, which is more effective than running in groups (if you need gold). The silver drops when you're in group and the loot are divided, it doesn't give you much. I do dailies almost everyday, from collosal up, in a party, and it gives me about idk, 100-200g? Depending if I'm lucky with the drops or not. And it took at least an hour to finish all four, sometimes 1,5 or almost 2. Compared to that, grinding alone gives gold much faster and more effectively. Secondly, about party, actually try making your own party. That's what I do. Of course if you're a dps, it'll be harder, but make your own. You can play the class you want if you make the party. Anyway, I do dungeons and trial runs a lot, in a party, but basically I see that people prefer to go with those they know, especially in higher level dungeons and more even in trials. There's no guarantee that if they look for other people, the one joining will be a good, or at least decent one. For me, i don't really mind with low dps-er but you know if it's too low, that means the others work more to cover that member, right? Oh I find that a lot, I sometimes go with random parties and when I'm unlucky most of my party members contribute nothing and that's sucks a lot. Not to mention if they just take the loot all the like while some others do all the work. That's why I usually go with my guildie or sometimes I get invitations from friends. I do make party for instances that I think I can handle in worse case, otherwise I prefer to play it safe.
Idk about the others, but I think most people prefer to go with those they know.