Jersey Shore, Justin Bieber etc etc. Popularity has absolutely nothing to do with quality.
except Chuck Norris it reflect quality
maybe I'm wrong, civ before was a segmented product, it is not for everyone, it have it own character, it own fans, and unique game quality. It control both micro and macro management on building empire, and it dealt with complexity of each element on building empire, like income, growth, population, health, sciences, and we being put in the middle of all of these problem and try to make it balances, both in macro management or micro management, from how we build improvement, city specialization, and all of these things.
But in my humble opinion, civ5 try to make a bridge to make civilization from a segmented product (like europa universalis, for me this game is magnificent, from the map, gameplay, historical event, this game is epic, magnum opus, but again not everybody can play and like europa universalis) to make it mass product that everybody can play it, easy to understand, instant, less micro more macro etc. I do understand why part of peoples here don't like civ5, and I do also understand why civ5 can be fun. But for me, civ5 is worst civ product with good potential. One things that very enjoyable in civ5, is the combat system (not the 1upt) even its better than europa universalis, archer really appear as an archer and siege weapon as a siege weapon not as crazy kamikaze or martyr who crushing his head to enemy city wall or huge army.
It is not whole of civ5 is bad or wrong, and not also the best civ product we can even call it a degradation in civilization game, but again this only my opinion.