I agree with the broader point, but I'm perplexed that the author is talking about dogfooding as a "sacred practice in the tech industry" in the context of customer support. Among big tech companies, customer support usually isn't seen a part of the product. If you work at Facebook, Google, or Microsoft, you don't try to go through the non-existent consumer support channels to resolve issues with your account.

Interestingly, in the company I currently work for, if an employee encounters a problem with the product, the expected way to report the issue is to open a ticket. Not in an different system with different people responsible for handling it, in the same ticketing system that customers use.

Exactly. That's the "smelling your own farts" part.