Yes, you’re right, as far as I’m aware - in that I think they need to be used as instructed to work properly. I also have a small one (3 cups advertised, 2 cups reality) but there are single serving ones, if you have the one down from me then it shouldn’t be too much for one person, but each to their own!
However my advice would be to stick the remainder in a jug of some sort. We freeze our leftovers as they’re useful for baking, ice cubes, iced coffee etc. Waste not want not
That thick coffee foam (crema) is a modern thing anyway and is the result of using an espresso machine. You get a temporary crema sometimes in a moka pot, but it’s not the same thing at all.
Don’t get me wrong, it does make for a delicious coffee, but next time you get snubbed just tell him yours is more traditional