I almost always played solo because I liked exploring and crafting and doing things at my pace. Whenever I had a group, I felt like I was pressured to move move move and finish as much as possible without absorbing the environments or reading the matching story lines.
I was able to finish a few of the low level instances, but was rarely able to find a group to run with and thus usually just skipped over any quests that required them. Sure, picking up some legendary gear would be nice, but I would have just loved the option to stroll through these quests on my own.