Actually, they didn't market their bikes as "more is better." They marketed their bikes as super light alu. That was their trick: "less is more."
It was up to the actual dealers to get word out and "warn" prospective buyers that they best served heavier riders.
Then, riders (and bike rags) began to put a positive spin on all this: i.e., 'dales transfer power directly, and such nonsense.
The various lies of cannondale marketing were exposed over time:
a. 'dales are super light bikes (not any lighter than other alu bikes with similar tube dimensions)
b. superior power transfer (not really: some flexibility ensures energy rebound through each stroke)
c. big tubes must be super durable: actually their tube walls were super thin, hence more easily dented)
What's really bizarre is how this forum in particular has fallen into groupthink labeling this bike as some sort of superior value. It's a niche bike, which serves certain riders well (heavy riders, crit mashers), at the cost of serious deficiencies in the eyes of other types of riders (lighter riders, century riders, riders who don't want to feel a pebble shaking their innards).