My children attend and have attended schools, both public and private where the attitude most certainly was one of provider and customer.
In both schools, one private and one public, the idea that he who pays the piper calls the tune is respected.
What if every parent wants different things, so you have upto 30 'tunes'. By all means say stuff, but to dictate is ridiculous.
That is why small groups of parents get together and present a united front.
It starts with a few parents unhappy with the fact that students from the private elementary school get placed in remedial or lowest streams in maths in all the high schools they attend, even those getting As in maths. From the grumbling a group forms. Much discussion goes on behind the admin's back, approaches are made to the school board members who are parents, and finally the administration becomes aware that a parents' maths committee has been formed. [True story, btw].
Or a group of African American parents suspects that black students are not getting a fair shake in the high school and get together to present proposals for a wide range of changes that they hope will result in less detention of black students, more enthusiastic encouragement by teachers of black students in honours classes, the hiring of more African American teachers, inclusion of more African American history courses and novels in literature courses, a spoken word poetry group, etc.
The pressure groups are well aware that the majority of parents are ambivalent or don't want to get involved or are even happy with their students' progress. But those pushing for change do not have to have all the parents behind them. All they need is a united front and a coherent set of proposals.
Dictation is not the right word for this. It is holding administrations accountable for their actions to those who pay the salaries of the administrators. In the case of the elementary school, fees are paid and parents expect results, not to see their students' life chances ruined by a bad teacher from age 12 to 14. In the case of the high school, high property taxes are paid and there is a very reasonable expectation of a return for that money in the form of a high school with a well earned reputation for excellent results for all students.