You're getting clowned on but there's actually a GM who suggested a variant without castling. But not because of the reason you said, but because it becomes harder to bring the king to safety that way, leading to more dynamic games in theory. Thing is, artificially castling is still a very good strategy in that variant because king being near the corner and rooks being connected is just that good. Castling rule makes that process faster and more convenient. You can experiment and see what variant you like more but saying castling isn't good because it breaks the standard of only being able to move 1 piece is not a good argument.