What does it taste like?
Like the human young, baby corn can't do many of the jobs we expect from grown-up foods: It doesn't have much nutritional value, and it doesn't have much taste either (again, it's not even pollinated yet). Its primary job is to look adorable and provide some texture to a stir-fry, but the vegetable can be a nice addition to soups, stews, or curries. It's rarely enjoyed on its own.
To really get the most out of it, you'll want it harvested a few days after the silks appear and not shipped around the world, which is possible in the States, but not common. The test of fresh baby corn is similar to hearts of palm. It's always going to have mild flavor though, for the reasons already mentioned (lack of sugar and starch, among them).
So the short answer: It doesn't taste like much. That's not necessarily a bad thing though. Not every veggie can be the sweet potato, nor should every veggie act like the sweet potato (kind of a try-hard self-promoter, to be honest). Sometimes you need a team player that rounds out the dish.
Like good parents, let's judge baby corn by its own merits and ambitions, and let's love it for the humble role it was born to play.