I admit I do not share your unbridled optimism. There's a word for what you're describing. It's slacktivism and it's not a good thing. If I may explain myself before I get downvoted into oblivion:

Basically all the internet does is raise awareness and in some cases shame someone publicly. So for something to change there are two options:

1. The person being shamed decides to capitulate because [reason].
2. Someone who has power over the person being shamed does something because they are now aware of an issue they weren't before, or they were and just want to save face.

Starting at option 1, I can tell you that these people feel no shame about what they're doing. If they did, they simply wouldn't have done it in the first place. And the outrage? Who cares. Just keep your head down and it blows over (slacktivism).

So then we look to a third party. In the case of a more traditional business, these might be the customers who refuse to frequent a business due to openly racist business owners. Or someone higher up the ladder throwing someone else under the bus. These are actually the 'activists' that have been spurred on by the 'slacktivists'. So in this case, rejoice! You may or may not have made a difference.

But guess what board members of schools do not have?

• Customers: parents will not en masse start pulling their kids out of school to go elsewhere to support teachers. Not going to happen.
• Bosses / people higher up the ladder: board members are at the top. Nobody is going to fire or reprimand them besides perhaps fellow board members. In this case however it's obviously about policies that the entire board puts forward.

So I'm sorry to say I can only conclude that you overestimate "the power of the internet". At best it's good for awareness campaigns, which sometimes spur on actual activists who make the changes we want to see. But 'the internet' directly does jack shit and gets bored / moves on way too quickly.