Your analogy is moot from the starting point. You can't compare a country and a gaming company. They're not managed by the same rules (you can unsubscribe from an MMO but it's slightly harder to do for a country), and they do not pursue the same objectives.
For a gaming company, it is
fundamental to follow the social evolution of both the potential and actual playerbases, because otherwise, the playerbase turns to competition (something which is easier to do than change countries). At the same time, you have to make sure that your choices are economically defensible (i.e. you won't develop content for a tiny minority of players within the game).
Consequently, starting from LK, Blizzard had to steer away from the BC and LK model because a) they realized it was no longer defensible, b) that the playerbase was changing and c) the whole MMO market was about to stagnate, making gaining new customers more difficult and churn high more likely. Based on those economical and social considerations, they made the decision of a) making end-game content less restrictive than it previously was, b) allowing easier catch-up for people who started mid-expansion and c) remove some of the infamous mechanics which led to player poaching and thus an unhealthy social climate withing the game (I'm referring to attunements obviously). Thus, we had LK. The LK model was not perfect (it lacked hard modes in its first tier - except Sartha) but at the end, we got a model which was holding up. Cata, unfortunately, messed up quite a lot of things, but MOP is coming along nicely to correct the above.
Btw, Mr. Canadian, where are the epixx I can get in dungeons in MOP, cause I only seem to get blues...