Gun fire blasts will damage planes and the flight deck.
Long, straight flight deck inefficient compared to angled deck.
The usual reason a battleship got bigger, was so that it would have more displacement for larger guns, and not more guns. (Eg, why would I put 27 8" guns on a montana?)
3 Bridges is a waste of displacement, not to mention exaust from the smokestacks would blind any men on the rear bridges.
Case mate side guns have been shown in WWI to be inefficient (low max angle), and easily take on water during rough seas.
Distance between boilers (beneath smoke stacks) to the rear of the ship is very great, it's inefficient to have a shaft bringing power that far back. (eg, IJN Tone had 4 turrets in front, 0 in back)
Like the others have said, bigger ship=bigger target, would be the first to be targeted in any battle.