I've noticed a recent trend in iPhone game development articles that implore, "Here be dragons, don't waste your time". Curious, I continue to read and find almost all games were developed by a single developer inside of a month. That's barely enough time to generate and playtest a central game mechanic, let alone develop and polish an entire casual game.
That's a fairly brazen ripoff, though changing the plane to a Sopwith Camel is enough to escape any legal troubles. It's just a pity this is what developers resort to when they lack ideas.
There's a pretty big difference between being inspired by games in the past (see below), and systematically copying one specific game piece by piece - name included.
I'd like to note that I actually hadn't played any game like Stunt Pilot when I wrote it, although I've since played Pilot Wings. Stunt Pilot was designed to be a playable version of air racing.
Come on, this game was dead simple to build (and he could probably build it again in half the time with the experience gained) and made $10K a day for a period. I would call that a tremendous success.
Turns out free doesn't work, and neither does dirt cheap. I am amazed that people will go into an area like video games, where you are free to make a truly unique, non commoditized product, and compete on margin.
I think people underestimate what it takes to make a good game that people will be willing to pay for. Take Flight Control. It's a very enjoyable, addictive game. However, if you take this same game and its mechanics, slap a different set of graphics that's not as polished, take away the highlight when you land or link a plane to its landing strip, change the sound effects, use simple randomization for where planes come from and their rate of appearance, and it's not going to be as big a hit.
The iPhone hardware and its built in apps set a certain level of expectation of polish. Graphics that would work on other environments won't cut it on this device, especially when there are a lot more options.
I think the whole world now knows that, if you build something good & it goes viral, you can make a lot of money for a while. Then, with the app store churn, if you don't get and stay in the top 10-25 app charts, and don't do serious promotion, your app is almost guaranteed to fade away.
Maybe it would be possible to develop a viral app (spreading over FB/Twitter) for the iPhone and let it spread with a bit more steadiness than relying on being in the top list.
Spend some time on game design quality!