It's all post-hoc rationalisation. They got caught in their own hype and released low-quality code. They fucked up, that's all, and it's a bit embarrassing that they won't admit it.
But also they built on it, and KDE 6 benefits from all that work and is an exceptional desktop.
But also they built on it, and KDE 6 benefits from all that work and is an exceptional desktop.