Well, but the Feywild isn't just "a magic forest" or even a set of magic forests -- it's the Faerie Realm. It's an alternate universe where the wild forces that lie slumbering in our world run free.

I don't think it's really that much of a downer to claim that while the forest near my house is touched by fey forces, that forest is still very much a "real" place -- mappable, measurable, razeable for the purpose of building a new castle if I really wanted -- and the true unbounded forest where the faeries actually live remains beyond the mushroom rings.