Will free schools benefit all?

My biggest fear for letting anyone setup and run a school is that it could mean segregation. If communities or religions think their children are not being properly catered for they'll go off and set their own up and while they may have to be open to other students (I imagine that'll be a pre-requisite) and have their curriculum reviewed they'll end up catering for certain races and religions at the exclusion of others and we end up with school ghettos.