Right but the games preform better on the 3GS than on the 3G.
GPS also works faster on the 3GS due to the faster processor and more ram. You're telling me you'd rather wait 3 seconds for the Messages app to load when it can instantly load on the 3GS? Multiple upgrades is far more significant than 2 little additions.
The addition of 3G chip and GPS is nothing compared to a spec bump.
Have you ever tried loading a page with EDGE? The difference between EDGE and 3G is lot more than 3 seconds.
That's great that they perform better, I would hope they would. But that doesn't change the situation. It would be like getting an HDTV without any of the content. Sure the picture looks a bit better than an SDTV, but it's still 480i content. Until you get the HD channels, a blu-ray player and a HD video game system your expensive upgrade is rather useless.
Right now there's no market for 3GS only apps. It's only been out 7-8 months and a very large portion of the iPhones out there are 2G or 3G. If a dev makes a 3GS only app it cuts their consumer base in half (at least).
Once the 4G comes out, most 3G owners will upgrade to the newest hardware and devs can improve their app quality. Albeit, they'll be better on the 4G.
You see the flaw in your logic, right?