When your pieces are sitting on the back row on their original squares, this is certainly poor strategic positioning for them. So, if nothing else, getting them out of the back row is an improvement. Getting them to the most strategically beneficial square is difficult, but getting them off the back row should be straightforward.
Castling is generally counted as a developing move as well. One positional positive is if your rooks are connected on the back rank -- meaning there is nothing else inbetween them. This gives the rooks the choice of what file to go to and allows them to protect each other, and potentially double on the same file.
I have a question for you Loomis. You said above that ''getting them to the most strategically beneficial square is difficult'', right?.
So, my question for you is ''do you mean what you said is the same as getting them to the most strategic position''?. I'll wait to your answer.
"Personally, I'm not too fond of his king move, as bringing your king off the bank rank exposes it to lots of checks and removes some of the safety you get from castling."
I bet he wasn't too fond of it himself, but the alternatives aren't improvements. 5. g3? Bxg3+ exploiting the pinned h-pawn. 5. Kd2 doesn't avoid the porblems you brought up about Ke2.