Dude, you give up too easily.
If parents get together, there are many ways for them to change the system. Just out of the top of my head, we could use the media, elected officials, etc...
School administrators are salaried people. They have to answer to somebody, most likely elected officials.
Of course, if the parents were united and involved in the first place, there wouldn't be any problems to begin with.
Been tried---failed. I've seen a couple of these efforts at making even MINOR changes in the curriculum instigated by parents. The "ed-biz professionals" simply listen politely to the parental comments, and then go ahead and do whatever the hell they wanted to do in the first place.
"School administrators are salaried people. They have to answer to somebody, most likely elected officials."
No longer. This was "once" true, when local school boards were controlled directly by local voters, and had complete say over hiring and firing and budgetary concerns. That power has moved from complete local control, to "county-wide" control, to state control, and is not-so-slowly moving to federal control.
"Of course, if the parents were united and involved in the first place, there wouldn't be any problems to begin with."
You fail to understand that these changes were STEALTH changes, and every effort has been made to conceal the true curriculum changes from parents.
I'm afraid you are VERY naive and much too optimistic. There is zero chance of reforming the public school system. The only possibility left to concerned parents is to "get the hell out".