I doubt you've ever used a firearm in your entire life if you believe the Wiimote is similar. The Wiimote is aimed at 2 infrared dots in the sensor bar, perhaps with an offset for top or bottom of the screen positioning. So pointing at a point on the screen is stupid, instead you have to see where the cursor is and change where its pointing off that which is slow and tedious compared to a mouse which has far greater percision and you can actually get used to a DPI setting so you are always spot on with your movements. Similarly you can get used to sensitivity settings on analog sticks to max out your performance. But the Wiimote you'll always be having to get your point or origin and then moving off that. Plus I find it annoying to constantly be holding the Wiimote pointing.

Also, if you pickup a weapon you've never used before you can too get a "bull's-eye". If the weapon is properly sighted and you are an experienced shooter, there's no reason you can't pickup any decent weapon and shoot with a high degree of accuracy. Honestly the Wii doesn't add any realism. It's different, that's about it. You either like it or don't, and I don't and you do.

I was skeptical about the dual analog sticks back when they were new for FPS games. I prefered 4 face buttons for movement and 1 analog for freelook. But it works out. I gave the Wiimote a chance too and as I said, the aiming doesn't work well enough for alot of gametypes.