Not at all. It was a very successful model!
Sales tell a different story. The kind of people who criticize such cars as being "a symbol of insatiable excess, arrogance and greed" won't buy any such expensive car regardless who make them and what kind of qualities they have - their concerns are largely political. On the other hand, those who want such an expensive car, will often want an imposing vehicle - and the W140 delivered.
Audi didn't even have a model in this segment until 1994. The 7 series was not really on a par with S-Class until the E38(while the E32 was interesting, reliability was bad). However, neither the A8 nor the 7 series surpassed the S Class in sales.