I work in Java every day, and I agree it's been a huge success. But I also don't think it's a good general purpose language. It's absolutely full of warts and gotchas and ergonomic problems and questionable design decisions that even the people who made them have come to regret.

But known history tells us that there is very little correlation between a language's success and how well-designed it is. Outside of software, too - I think the archetype for this phenomenon is probably VHS and Betamax.