In the U.S. it is made by meaderies with honey they purchased whereas in France mead is made by beekeepers with their own honey. So in France it is an apiarian product (as honey, wax and pollen are) made by beekeepers to find a new market for their honey. It is therefore logical that in the U.S.A. mead be entered in beer competitions. The concours général agricole (the largest national competition in France for agricultural products) judges mead along with honey in the "apiarian products" category. On one side it is a fermented beverage (those making mead commercially also make beer or wine), on the other side it is linked to honey (same producers).
In France it is fairly traditional (honey, yeast, water.) I do not have enough information to tell which honey is used. Th only major thing I know is that in Brittany buckwheat is commonly used (it is their traditional cereal, which they also use for crêpes for instance.) Buckwheat honey (and mead) is strong flavored, described as malty (by those who like) or as barnyard-like (by those who do not.) These taste and flavor are also found in mead, leading to a strong mead.
In the U.S., meads are more diverse, including herbs, petals or fruits, some meads are sparkling. Due to the difference in the tastes of French and Americans, it could be expected that mead be sweeter in the U.S. But mead is generally associated with honey and sweetness, so this is not sure. The concours général agricole has two categories, dry and sweet whereas in the U.S. categories are traditional, melomels, methegins, etc. So half of the American production may not be called mead in France.