It's really funny to hear this. If you look at press/reviews/OSS forum comments of it around launch time, people thought it had an excellent interface, because it was being compared to sourceforge.
Then github came, and by comparison, the interface looked like crap.
But you end up with this kind of weird history rewrite where the view becomes "it was always ugly", when it was probably best-around for at least 2 years, maybe more (depends on your view of early github)
"Google Code, by contrast, didn't seem to have a clear purpose other than hosting open-source projects. It was a kind of souped-up SourceForge, rather than a serious GitHub competitor. Google certainly had the resources to improve it, but didn't have the motivation that GitHub did -- and we see the results."
It was in fact, meant to be a better-than-sourceforge alternative, because Google viewed sourceforge as a harmful-to-opensource monoculture, and competition was desperately needed. github is a monoculture, but it doesn't seem, at least right now, to be harmful.
As for "serious github competitor", it was never meant to be that. It predates github by over 2 years :)