I've asked a friend of mine who was at the time close to the situation when the APPO school was built, the stadium they put in is one of the state of the art stadiums in the state but lacks a severe amount of seating for sports.
It baffles me when you go to a school and half the attendance has to stand because of lack of seating, so when I asked, their reasoning "why fork out all the extra money for a 5,000 seat stadium when maybe one day out of the year they will house 5,000 people." The Mtown/Appo game. Any other game Appo would be surprised if they drew half that amount of attendance.
I guess where I'm going with this is why should sallies have to fork out the money for 5,000 seats when they will only draw that against Middletown. Like jawnsky said, the sals/stm rivalry will begin to deminish because of competition soon, if not come to a complete Hault. Don't get me wrong, I would love nothing more than for every school to hold 5,000 people but to be honest, those two schools mentioned are probably the only ones that can draw it. Smyrna might start being able too if they stay competitive year after year, with their community still growing and with a small town feel, they would be my only other school that could draw that amount but even their stands can hold 2,500 at best.
The fan support for some schools just aren't there, I remember going to the William Penn/Caesar Rodney playoff game a few years back, I was quite surprised by the lack of attendance, you could fit both schools fans on the same side, which is pathetic for a playoff game.