Miners don't want the network to split, simple as that. If there comes a day that miners or the community are willing to destroy Bitcoin, by having a hard fork that separate the key stakeholders (or economic agents), then Bitcoin is doomed.
So, this applies:
Thus, it'd be more profitable for the miners to mine what people follow and not what is benefiting them in the protocol level.
They mine what the people want. Thus, their fork will become meaningless if the people say so. That's why they'll never have more power than the people. Because, people are essentially the miners' incentive; the miners' income comes from the people's “vote” in the market. They're dependent from the people.
I think that I know cleared it up, thanks ranochigo!