Uh, you stated the answer yourself. Corporations are accountable to their shareholders. They maximize profit, that is the only thing they do, and that is in fact a legal obligation that public company boards can be sued for breaching. You call them "publicly-owned" corporations but that is incorrect, they are in fact PRIVATELY OWNED.
The government including regulatory agencies like the FCC have a responsibility to take public interest into account - yes it is never done perfectly - but the FACT is that the decision-making process for governmental entities is entirely different than it is for private corporations.
The corporation does whatever the board of directors want it to do, within the bounds of the law and what the other shareholders will let them get away with before firing them. Money is a big deal, but as Google's actions in China have shown, money is not their only motivation. I'm not saying they're altruistic or anything, but I don't think they're scheming in public a way to screw over the internet for money.
Yeah but come on, the decision-making is not "public". The average shareholder, if he even holds shares directly, really has no way to seriously influence corporate strategy other than to sell the stock. In any case, the whole premise of a democracy is that citizens are able to have equal or near-equal influence. That's why we have one person, one vote. In shareholder capitalism, the more you own, the more votes you have. Those two principles are directly in opposition, making the suggestion that it's a tossup whether corporate or government decisions are equally influenced by public interest categorically false.
The government including regulatory agencies like the FCC have a responsibility to take public interest into account - yes it is never done perfectly - but the FACT is that the decision-making process for governmental entities is entirely different than it is for private corporations.