Why would you say it’s not the real thing? Defining champagne to be made in a specific region of France is a cop-out. That is almost a meaningless definition because even within the region there are different types and recipes being used. It’s not like they have magical grapes. Sure it might taste a little different due to regional differences but that doesn’t make it worse or even not champagne. Whether it’s quality has to do with the vineyard rather than the geographic region.

If it’s bad because it cuts corners and uses cheap ingredients then that’s the problem.