Did someone really just compare Bioshock to the best selling shooter game of all time?
Nope, Duck Hunt was never once mentioned in this thread until your post.
I also partially disagree with your assertion that the comparison is completely flawed: while the pointer controls DO add greatly to the game, there's little other reason to buy Reflex, and I would argue that the vast majority of people who cared to do so either purchased or played the game sometime in the past 2+ years, especially since no one really saw Reflex coming until it was announced. Bioshock, which was much less of a sensation than Modern Warfare, was only out for one year, and a PS3 release was heavily rumored (hoped for?) almost from the beginning.
It's not a perfect analogy, but it's far from imperfect.
Too bad I never said the comparison is completely flawed. And why is there little other reason to buy Reflex? If you're a Wii only user, it's your first time having the game on your platform, and it's another Call of Duty game to buy if you enjoyed Call of Duty 3 and/or World at War. And I would agree that most people who wanted to play the game have already played it, otherwise the Wii version would be the best selling by far. But that doesn't change the fact that whether it's a year or two years, Reflex had the advantage of motion controls, online, and one of the most popular brand names in gaming. Bioshock on the PS3 didn't. Most of the hype about Bioshock had died down after the first year, while the Call of Duty hype never stopped for a second (it had actually been kicked into overdrive with the MW2 launch). Also, if your analogy isn't perfect, then it's imperfect.
Replace "completely" with "too" if it makes you feel any better. Now that that seismic shift is out of the way...
And yes, if you're a Wii-only owner who's been dying to play Modern Warfare, Reflex is your chance. I repeat, though, that this is a comparatively small group.* As to the other features you listed, I argue that the brand name portion helps a lot, but that Call of Duty had such a powerful brand name that the vast majority of people who were interested in playing the title did so sometime in the past two years on at least one of the three platforms it was released on. This does not annul the "brand name" argument, nor is it intended to, but it does temper the statement that millions of people should have purchased Reflex by now.
As to online, that argument is a wash. Call of Duty games are intended to have online, and the HD/PC versions do. Bioshock is NOT intended to have online, and the 360/PC versions do not. You may argue, successfully, that online in shooters is helpful to sales, but when we're talking about one-to-two year old ports, you know what you're signing up for already: the only difference online would make in these sales is if Reflex did NOT have a feature that players expected out of it.
Regarding the Bioshock hype:
That's quite a shelf life for something that's died down. Or are you arguing that Reflex, a two-year old downscaled port of a game most interested gamers have already played, should be benefitting more from the release of Modern Warfare 2? If so, it's an interesting argument: I don't agree with the premise, but I confess that I have as little solid data to point to as the other side, so I'll satisfy stick with "it's possible, but unproven."
And yes, an analogy that isn't perfect is imperfect. Let's move that "completely" from in front of "flawed" to in front of "imperfect."
*Compared to the people who wanted to play Modern Warfare in the first place, that is.