I don't think anyone is calling them evil due to the app store restriction here. But they definitely stole the guy's app and logo. That's both illegal (at least the logo part) and immoral.

Reject the app, sure. Build similar functionality yourself, perhaps a bit scumbaggy but also probably legal. (This crowd still hasn't forgiving Microsoft for doing that 20 years ago.) Do all of that and steal the logo too and you've crossed the line.