I keep my phone in a case. Use it often actually. In fact, when the 3G first came out, I bought it, and it's as good now as it was then. No scratches, cracks, or anything. Then when the 4 came out, I upgraded. Since then, same thing; no scratches, or issues. Never experienced the "Antenna" issue. Lastly, I guess my hands are clean, and free of 'fluids". I clean the screen off every now/then, but you'll get that with any/all touch screens, not just the iPhone.
If you don't like them, don't use them. I somehow see you with one of those cool flip phones, with big numbers, and rubber bumpers...what do they call those?? Oh ya!!!! A Jitterbug....