You just answered your own question.
Seriously though, the Northwood generation might have been good (though Intel arguably got lucky in that AMD's initial 130nm process turned out to be a dud, stranding the Athlon XP at low clockspeeds for the better part of a year), but Willamette was underwhelming, Prescott was absolute garbage, and probably the only reason they even bothered releasing Cedar Mill was to fine-tune their 65nm process ahead of Core 2's release. 1 good design out of 4 isn't exactly the best batting ratio.