Solo doesn't have to mean easy though, think of RDM maat for instance. There were a LOT of people that had trouble with him, he was solo, he wasn't easy for a lot of people.
I wouldn't mind light party stuff for storyline, I'm totally not opposed to that.
Like it was stated earlier in the thread though, solo really doesn't have to mean easy. You can have VERY challenging and fulfilling solo content that can test your skills. 1 person doesn't = hurr let me just go cast stone and I'll watch a pretty CS after.