Yea, I've tried some of the games ported to the iphone and they all suck to play if they weren't written for a touch screen. Even "action" style touch screen games are difficult to control. Even the ones were they have added an on screen joystick and buttons.
This is a good point, Amiga games in their original state do not translate well to touch screens 
If the game concept is good it is better rewritten to take advantage of the modern interface 
If I'm really honest, my enthusiasm for an Amiga emulator on a modern smart phone has dropped to zero... The Amiga and it's software just were not designed with touchscreens in mind...
