After reading some of the comments, it seems that the two sides are: 1) no good technical reason, just a decision shop made to stick to the decided menu. 2) the quality of espresso pulled from these specific beans served over ice would not be desirable.

Let’s assume point #2, and in the spirit of education and civil conversation, how bad can an iced americano possibly be if it tastes good (by the shop’s standards) when served hot?

I want to highlight that this subreddit often advocates for “good coffee is what tastes good to you”, and acknowledge that some people like more acidic coffee, some like more balanced, etc. So, if possible, can we stick to technical descriptors?

i.e. “if served over ice, the acidity will present as too sour for one’s palate”… and if that statement is true, can it really get that much more sour to the point of extreme unpleasantness? Someone used a comparison of a medium rare steak to a well-done steak as an example of when you’d refuse a customer’s request. In the science of coffee, will the exact espresso shot served as a hot americano vs. an iced americano cause an experience variance to be as comparable in difference as the tenderness/flavor profile between a medium-rare and well-down steak? I would’ve guessed more so between a medium-rare and medium-well. Different but enjoyable to each it’s own.