I agree that it is an acquired taste. If you've been raised drinking Yerba Mate you probably think it's great, but I don't think that I could drink it long enough to acquire the taste. Just like the "down under" staple/treat called Vegemite (a yeast extract) is relished by those who grew up with it, I still cannot go back for seconds.
Yerba Mate is a tea and I do not care for hot tea although I drink iced tea daily. Perhaps if I tried it cold it would be more appealing.
Here's a link that will go into history and details: