Any engineer that takes issue with that statement has never spent a day dealing with rude, angry customers and has no accurate frame of reference to draw up a response.
I remember some time in support, most customers weren't rude. It's boring calls to register on the service, moving out to a new address, or confirming identity.
If telephone support is the final option after email doesn't work, I feel entitled to be angry. That doesn't mean I have to be rude, but I let the call center person now that I am fucking angry if I wrote 2 emails/support tickets already and they haven't solved the problem.