One of the points it makes is that shareholders have very little power in practice, as even if you own a million dollars of Apple shares, that's only 0.00007% of the company. Not exactly enough to force through a motion on your own.
And if you think you'll build up a coalition to get a majority? Good luck doing that when you can't even find out the names of other shareholders.
Minority shareholder lawsuits? They're actually a negligible force; rare, unlikely to succeed, and low impact even when they do.
And that's without getting into 'preference shares' that grant CEOs outsized voting rights.
The book argues management can neglect shareholders' interests with impunity for these reasons.