Computers are stupid. And you get in the habit of giving instructions in a particular way. Tea first tells the computer what you are asking for, Earl Gray provides one parameter, not another. So the order comprises the item, flavor, and tempurature. And I bet there are plenty of people out there who like Earn Grey cold. I've never minded it when it cools off. No need to heat it, just drink it. So his order makes complete sense. Plus, he may know something you don't. Maybe if he doesn't order it that way the computer is programmed to ask questions. So his order might be the fastest way to address all the variables that computer might ask. It also could be for the computer on the Stargazer which might not have been quite as refined. When you develop a habit it can be hard to break.
But again, if we need temperature as a parameter, why not the amount?