You sound like you're on the autistic spectrum, struggling to understand basic human social interactions like some kind of hyper analytical artificial intelligence. The server was being helpful, not bossy. That was a great example of customer service going beyond reasonable expectations.

The OP could have said "no thanks" and continued with his original order. Simple as that. It seems that your social cognitive circuitry is overloaded by someone acting like an actual person instead of a simple robot.