Yea I mean the ObjC vs Swift thing.... a matter of preference. I trust Steve Jobs more than I trust Tim Cook. I hate the feature creep in Swift. I hate Swift optionals. ObjC compiles faster than Swift. The ObjC ABI/runtime is superior to the Swift ABI/runtime (which allows for cool stuff like https://cycript.org). I like the dynamic typing a lot. Managing headers is a non-issue for me, I just consolidate everything into one monolithic header file.
I've worked in pretty big ObjC codebases (1M+ lines) so I know most of the tricks to deal with complexity. For Swift, max I've dealt with is 100k lines and it was crippled with tech debt. Frankly, the other engineers on the team were terrible, so maybe that's why. They abused the shit out of RxSwift and refused to use the `!` force-unwrap optional feature