I'm going to judge people on the length of their starbucks order
Are you really gonna do that?
Yes, mostly when it's possible to ask them
I think that's a petty reason to be judgemental. You should reconsider this.
I'm doing it because it gives me pleasure.
But making that kind of judgment will make people think you are mean and rude. Wouldn't there be other ways to find pleasure? Granted, what you are doing seems harmless, but I think society will think you are weird so maybe look for an alternative?