Not sure if the pitch would fit if you turned it 90 degrees and even if it did you'd only have two sides closer to the seats (the ends) and the sides which are generally premium seats would be further from the pitch than they are currently.
Not suggesting it's an ideal solution but it's a possible low-cost improvement to the present set-up
Fans effectively sit or stand where they want, apart from AB Test Matches and Play-offs, as there is no effective policing of premium seats.
Phoenix Fan! He stands where he wants! :-)