Originally Posted by
Proudelitist
It is in generally poor taste for an employee to bad mouth a product they offer and/or sell. Everything offered onboard an aircraft is there because of a contract or agreement, as such, employees who denigrate such a product are operating counter to their employer's wishes. It's also poor practice to criticize a customer's choice, scold, or otherwise guilt trip a customer about their choices.
It is worth a complaint, despite other comments in the thread about it not being a big deal. It's not the soda itself, it's the issue of employee behavior when the employee is the face of the company.
I think the flight attendant could care less what United's wishes are. And just because there is a contract it means Coke Zero is good for you?
Actually, it is good sales' practice to criticize a customer's choice. Salespeople often upsell people, and as such it is beneficial to them to make the customer doubt whether or not they made the right choice (initially, by choosing something cheaper).
I hate rental car salespeople, but they often get customers to upgrade their vehicle choice (at great cost) or to add on unnecessary things (the equivalent of rust protection for used car salesmen). As such, they are "doing a good job" (for themselves)