We Can’t Even Sugarcoat It
It’s clearly wrong, no matter how you look at it. We can’t even attempt to excuse this guy’s conduct, which is to throw his garbage on the floor whilst the restaurant is full of garbage bins. When you’ve finished your coffee (though we can’t see how it would be pleased with so much sugar, that’s beside the point), the decent thing to do is dispose of your trash.
The coffee shop employees are there to make our coffee, serve our pastries, and clean the floor from time to time, but they aren’t our personal maids. It’s polite to tidy up a mess you’ve made and respect the workers and the venue.