It really bugs me when people make extremely blanket statements like this.

This is a huge success story that I was part of: https://cloud.google.com/customers/gearlaunch/

At our peak, we were processing $500,000 of online orders per day and spending about $5k/month on our entire GPC bill. It was a rounding error compared with our income.

The biggest expenditure was actually on the Postgres database servers that we needed for our analytics, not on AppEngine.