The A's teams of the early 2000s were better than the 2006 team. They had Giambi, Tejada, a healthier Chavez, and better pitching as well.
There were two or three of those ALDS series where they had them in control and should have won if not for clenching and blowing it.
After sweeping the Twins in 2006, the A's then got swept by the Tigers. What do you say to that? Did what made them good enough to beat the Twins suddenly disappear in a few days? No. They followed up a great series with a terrible one.
The only thing that's really up for debate is how the patient philosophy of the A's hurts them in the playoffs when facing better pitchers who throw strikes more consistently.
If you think the ultimate goal of the A's isn't to win a World Series, you don't know anything.