Everyone always says Eureka is tuned for partying up. I took that as a challenge to learn to survive solo. And I enjoyed it in that context. You get the early levels without the exp loss, that gives you time to explore and experiment and learn. Find what you can and can't comfortably do. Learn the enemies, placements, aggro type, etc.

I suspect the crowd that may have enjoyed Eureka the most is the players that enjoy that learning process. Anyone looking to just turn their brain off for a bit is going to have a bad time if they don't first learn when it's safe to do so.