Did I just hear priest and an archer class have low solo capability? That's where I stopped reading that post. Ask anyone who knows what they're doing and they'll tell you otherwise. I can think of a lot of people on the server that soloed priests and bard / dancers to high level or trans. And really, it's quite easy.
However, you are right. Most people don't take other people on leveling with them. But that is a game mechanic flaw. When you get to top-end leveling, leveling with other people will slow you down. A lot of the best leveling is done solo. When you're one shotting stuff and what not especially.
