I'm pretty sure the motivating factor is waterproofing. The more places where the insides of the phone need to connect to the outside, the harder it is to protect from water damage.
On that note, wtf is up with inductive charging? It's been around since the 90s at least, with the first phone maybe the Palm Pre around 2009. It's super convenient and you'd think Apple would have leaped on that feature, to drop a connector.