That's the part so many people miss with crap like this: they're not saying it's the best, or that it's the favorite, only that it has broad general appeal.

In the US, Miller Lite is nobody's favorite beer (outside of a handful of devotees, I'm sure), but it's a beer that any beer drinker can fall back on and locate just about anywhere. It's not excessively high ABV, not overly hoppy, not sweet, low calories, doesn't sit heavy, isn't strictly for warm or cool weather, and reasonably priced.

Demographically, it is drank by college kids, sports spectators/tailgaters, old guys down at the social club, golfers, rednecks, wannabe rednecks from the suburbs, bachelorette parties, rock show attendees, and pretty much anyone anywhere beer is being served.

For those reasons, it's likely one of the top 5 "most popular" beers in the US.

Everyone saying they're local regional favorite or specialty craft brew is better are just missing the point.