I see the OP's point. I'm sure there are people out there who are fairly poor, but do have some disposable income, who have non-horrible PCs but don't want to spend $20 or $30 a month on Internet. And if you consider that the Internet at $20/month (a fairly low rate), is $240 a year, it's not inconceivable that someone might decide that wasn't worth it but buying one or two fairly new games that would run on their PC (as Civ5 probably would), for less than half the cost, would be worth it. And it's not that bad not having the 'Net, especially if you aren't used to it. I didn't have it until 2006; I played plenty of non-top-end games during that time, including Civ4. I didn't miss the Net much when I didn't have it. Although I did miss not having the Civ4 patches that made it run much more efficiently once I heard about them.
There's also a good number of people who could afford Internet, but live in places where halfway decent Internet isn't available, and dial-up is the only option. Some of these people know there's faster options elsewhere, and feel dial-up is so slow as to not be worth getting. And they're kind of right, what with the image-laden Internet these days. On the other hand, a lot of them like the area where they live, and don't want to move just for Internet.
And sure, you could theoretically bring your computer to a Starbucks or Internet Cafe or wherever to activate it, but what if you have a desktop? Would you really want to do that? The poor probably are more likely to have comparitively inexpensive desktops, too, so you can't just assume that they have laptops they can bring to the library or wherever there is Internet.
Most of the people without Internet probably aren't browsing these forums, either. Or if they are, they probably are at a library. Which doesn't easily solve the problem if they have a desktop or the library doesn't have public-access WiFi.
It also blows if you are in the military and don't have consistent Net access. From what I've read, American military bases do a pretty good job of stocking new games, but that doesn't mean you have Net access all the time. So a soldier could buy Civ5, only to find out they couldn't play it for a couple weeks until they got Net access.
The way Microsoft confronted this was its phone activation option in Windows/Office. 2K probably doesn't already have a big call center, but that is one possible way to resolve this issue.
