Pretty much every data connector has its pins exposed to the air and subsequently ingress of dust and liquid when not mated. Having a big metal enclosures/ground planes/shields around the connector is about electrical noise control and sometimes to a limited degree about preventing mechanical damage.
The old apple connector was awful, prone to breakages and pin-lifting due to "real humans" using the devices, it also was a significant pain to replace in the iPod Touch due to its wide body and numerous pins ( at least the phones had a replacable flex lead containing the dock connector ), it was also exceptionally good at picking up crap (lint, paper, body gunk, drinks ... everything that you'd think people wouldn't in their right mind have near it ). I like that it's been changed around to the lightning connector, yes the pins are exposed on it, but it would seem that for a portable device that's floating around in a lot of random environments, the lightning cable is the one that gets the least exposure ( compared to the device ) as it just sits at home waiting till the user returns to charge up their device again. The most common problem we've been encountering is just the socket on the phones filling up with lint over time causing the connection to fail due to the inability to fully insert the plug - thankfully easy to fix of course.
The MicroUSB connector on phones usually are mashed due to people deciding "No, it really MUST fit this way". The SONY Xperia with the Micro-A was a wonderful disaster in that respect ( yes, I know the key is offset to prevent incorrect insertion, but it's useless against determined humans ), or due to looser tolerances the tongue gets partially sheared away when the phone is dropped on the connector while plugged in.
Who knows how people manage to break things in strange ways, but they do, "we" might not, but "they" certainly do.