I think the issues that Bill's pointed out above are more the reason for school funding initiatives getting voted down than a selfish or unwillingness for schools to excel. The attitude is more of "throwing good money after bad...FIX the problems and we'll give you more" type of thing.
Unfortunately, the teacher's union won't hear of anything that challenges their members' competence, or asks for accountability. Equally unfortunate is the administrators' unwillingness to concede that the management of schools is bloate, overly bureaucratic, and generally out of touch.
There's issues on both sides..and I think voters are tired of the bickering amongst administrators and the NEA; and watching the waste.