It was much more than that. jQuery made difficult things easy and paved the way for future technologies by using browser specific abilities and providing a unified API for developers to use.
It also standardized around a plugin architecture making it easy for people to write code others could easily reuse.
If you think there is only one iE6 bug that jQuery helped alleviate you'd be wrong. There are thousands of quirks/bugs/proprietary crap that jQuery handled for web developers.
Reducing it to an IE6 bug fix is out of touch with reality.
