I think the difference is that heroin is "cut." Meaning they have the full amount, but they dilute it (although the full amount will kill you, but I digress). This is closer to brewing beer. You might want the beer to one of those high abv beers in the 9% range, but you decide you don't want to wait for that, so you stop when it is only at 4.5% and you end up drinking Budweiser.
It is a new mechanic, it just has the same name as a Civ4 mechanic. The very fact that Civ4's feature wouldn't work in Civ5 means that it's not the same thing. This is very different from a Madden game, where the core gameplay remains mostly the same aside from the new feature and, often, there will be no new feature, just updated rosters and graphics. It's an entirely different system.
I think your criticism demonstrates a fundamental misunderstanding about the game development process and computer programming. I also want to point out that more is not always better. A feature has to be carefully added to avoid just creating noise with no benefit. Remember Soren's 1/3 remove, 1/3 new, 1/3 the same formula? While it doesn't require mathematical rigor, it does help demonstrate the concern to a degree.