Let me simplify. If you wear a SHOE, it protects your FEET from DIRT. If you wear a SANDAL, it allows the DIRT to get on your FEET. Got it now? Not sure how you fail to understand how having a gaping hole at the bottom charge\sync port could defeat the purpose of a PROTECTION CASE system, hehe. Especially given your sentence acknowledging that you realize dust, dirt, and debris would be allowed in through the hole.
----------Thank you for simplifying this for me with your vivid analogy as well as confirming that my statement was indeed what you had meant in your original post. I just wasn't sure if there was something in addition to that, that I may have been missing.
I'm a 4 year Sena user. I bought both with and without the port. Ended up returning the one with the port opening. It's just strange. When I had a Samsung Galaxy S 2, it might have been useful since the thing constantly needed charging, but with an iPhone 5, having a hole at the bottom makes it look cheap and gimmicky and takes away the entire reason I own the case (to protect the bottom of the phone). The UltraSlim classic is perfect for my needs. The black on my white iPhone 5 looks great and fits perfect and allows me to keep my phone nekked.