I don't remember anybody panning it. I'm probably an outlier[1], but do remember a friend of mine going from broke to making a good living off it through affiliate marketing within 3 months.

[1]Early on he quickly became one of Google's biggest customers, even working alone. He was invited to the first Google Zeitgest. These days he spends in the multiple tens of millions per year on Google.

I haven't heard anyone with volume saying fb ads work.